Solution: Let m be the first term of the AP and d be the common difference Let I be the GP’s first term and s be the common ration The Ap’s nth term is given as $t_{n}=a+{(n-1)}d$ in which the first...
If the sum of p terms of an A.P. is q and the sum of q terms is p, show that the sum of p + q terms is – (p + q). Also, find the sum of first p – q terms (p > q).
Solution: An AP’s sum of n terms is given by ${S_{n}}={\frac{n}{2}}(2a+(n-1)d)$ Where the first term is 'a' and the common difference is 'd'. It is given that $S_{p}=q$ and $S_{q}=p$ $\Rightarrow...
If $\theta_{1}, \theta_{2}, \theta_{3}, \ldots, \theta_{n}$ are in A.P., whose common difference is d, show that $\operatorname{Sec} \theta_{1} \sec \theta_{2}+\sec \theta_{2} \sec \theta_{3}+\ldots+\sec \theta_{n-1} \sec \theta_{n}=\frac{\tan \theta_{\mathrm{n}}-\tan \theta_{1}}{\operatorname{sind}}$
Solution: It is given that $\theta_{1}, \theta_{2}, \theta_{3}, \ldots, \theta_{n}$ are in the form of A.P., and $d$ is the common difference, We now need to prove that $\operatorname{Sec}...
If $a_{1}, a_{2}, a_{3}, \ldots, a_{n}$ are in A.P., where $a_{i}\lt{0}$ for all i, show that $\frac{1}{\sqrt{a_{1}}+\sqrt{a_{2}}}+\frac{1}{\sqrt{a_{2}}+\sqrt{a_{3}}}+\cdots+\frac{1}{\sqrt{a_{n-1}}+\sqrt{a_{n}}}=\frac{n-1}{\sqrt{a_{1}}+\sqrt{a_{n}}}$
Solution: It is given that $a_{1}, a_{2}, a_{3}, \ldots, a_{n}$ are in the form of AP in which $a_{i}\lt{0}$ for all i. To prove that: $\begin{array}{l}...
Find the sum of the series $\left(3^{3}-2^{3}\right)+\left(5^{3}-4^{3}\right)+\left(7^{3}-6^{3}\right)+\ldots$ to (i) $\mathrm{n}$ terms (ii) 10 terms
Solution: As per the question $\left(3^{3}-2^{3}\right)+\left(5^{3}-4^{3}\right)+\left(7^{3}-6^{3}\right)+\ldots$ Let's assume the series be...
If the $\mathrm{p}^{\text {th }}$ and $\mathrm{q}^{\text {th }}$ terms of a G.P. are $q$ and $p$ respectively, show that its $(p+q)^{\text {th }}$ term is $\left(\frac{\mathrm{q}^{\mathrm{p}}}{\mathrm{p}^{q}}\right)^{\frac{1}{\mathrm{p}-\mathrm{q}}}$
Solution: The $n^{\text {th }}$ term of Geometric Progression is given by $t_{n}=a r^{n-1}$ in which the first term is $a$ and the common difference is $r$ $\mathrm{p}^{\text {th }}$ term is given...
The first term of an A.P.is a, and the sum of the first $p$ terms is zero, show that the sum of its next q terms is $\frac{\text { is }(p+q) q}{p-1}$. [Hint: Required sum $\left.=\mathrm{S}_{\mathrm{p}+\mathrm{q}}-\mathrm{S}_{\mathrm{p}}\right]$
Solution: It is given that the first term is ' $a$ ' and the sum of first '$p$' terms is $S_{p}=0$ We now need to find the sum of the next 'q' terms So, the total terms are $p+q$ As a result, Sum of...
The third term of G.P. is 4. The product of its first 5 terms is (A) $4^{3}$ (B) $4^{4}$ (C) $4^{5}$ (D) None of these
Solution: Option (C) 45 is correct. Explanation: It is given that the third term of G.P, ${{T}_{3}}~=\text{ }4$ We need to find the product of first 5 terms It is known that, ${{T}_{n}}~=\text{...
In a cricket tournament 16 school teams participated. A sum of Rs 8000 is to be awarded among themselves as prize money. If the last placed team is awarded Rs 275 in prize money and the award increases by the same amount for successive finishing places, how much amount will the first place team receive?
Solution: Let the sum got by the lead position group be a Rs and d be distinction in sum As the thing that matters is same subsequently the runner up will get a – d and the third spot a – 2d, etc...
In a potato race 20 potatoes are placed in a line at intervals of 4 metres with the first potato 24 metres from the starting point. A contestant is required to bring the potatoes back to the starting place one at a time. How far would he run in bringing back all the potatoes?
Solution: Given at start he needs to run 24m to get the main potato then 28 m as the following potato is 4m away from first, and so on Thus the succession of his running will be 24, 28, 32 … There...
A side of an equilateral triangle is 20cm long. A second equilateral triangle is inscribed in it by joining the mid points of the sides of the first triangle. The process is continued as shown in the accompanying diagram. Find the perimeter of the sixth inscribed equilateral triangle.
Solution: Say ABC is a triangle with $AB\text{ }=\text{ }BC\text{ }=\text{ }AC\text{ }=\text{ }20$ cm Let’s say that D, E and F are respectively the midpoints of AC, CB and AB that are joined to...
We know the sum of the interior angles of a triangle is 180°. Show that the sums of the interior angles of polygons with 3, 4, 5, 6, … sides form an arithmetic progression. Find the sum of the interior angles for a 21-sided polygon.
Solution: It is given that the sum of interior angles of a polygon having ‘n’ sides is denoted by $(n-2)\times {{180}^{\circ }}$ The sum of angles having 3 sides i.e n $=\text{ }3\text{ }is\text{...
A carpenter was hired to build 192 window frames. The first day he made five frames and each day, thereafter he made two more frames than he made the day before. How many days did it take him to finish the job?
Solution: It is given that on the day first he made five frames then 2 frames more than the previous i.e. 7 and then 9 and so on Therefore the making of frames each day forms a sequence of 5, 7, 9…...
A man accepts a position with an initial salary of Rs 5200 per month. It is understood that he will receive an automatic increase of Rs 320 in the very next month and each month thereafter. (a) Find his salary for the tenth month (b) What is his total earnings during the first year?
Solution: It is given to us that in first month the man’s salary is Rs.5200 and then it increases by Rs.320 every month Therefore, 5200, 5200 + 320, 5200 + 640… will be the sequence so formed of his...
A man saved Rs 66000 in 20 years. In each succeeding year after the first year he saved Rs 200 more than what he saved in the previous year. How much did he save in the first year?
Solution: It is given that the total amount saved is 66000 in 20 years, therefore ${{S}_{20}}~=\text{ }66000$ Let ‘a’ be the amount saved in first year. Then every year if he increases Rs. 200 every...
150 workers were engaged to finish a job in a certain number of days. 4 workers dropped out on second day, 4 more workers dropped out on third day and so on. It took 8 more days to finish the work. Find the number of days in which the work was completed
How about we expect x to be the quantity of days in which 150 laborers finish the work. Then, at that point, from the inquiry, we have \[\mathbf{150x}\text{ }=\text{ }\mathbf{150}\text{ }+\text{...
A manufacturer reckons that the value of a machine, which costs him Rs 15625, will depreciate each year by 20%. Find the estimated value at the end of 5 years
Given, the expense of machine \[=\text{ }\mathbf{Rs}\text{ }\mathbf{15625}\] Additionally, considering that the machine deteriorates by 20% consistently. Consequently, its worth after consistently...
A man deposited Rs 10000 in a bank at the rate of 5% simple interest annually. Find the amount in 15th year since he deposited the amount and also calculate the total amount after 20 years.
Given, the man saved Rs 10000 in a bank at the pace of 5% basic premium yearly. Subsequently, the interest in first year \[=\text{ }\left( \mathbf{5}/\mathbf{100} \right)\text{ }\mathbf{x}\text{...
A person writes a letter to four of his friends. He asks each one of them to copy the letter and mail to four different persons with instruction that they move the chain similarly. Assuming that the chain is not broken and that it costs 50 paise to mail one letter. Find the amount spent on the postage when 8th set of letter is mailed.
It's seen that, The quantities of letters sent structures a \[\mathbf{G}.\mathbf{P}.:\text{ }\mathbf{4},\text{ }\mathbf{42},\text{ }\ldots \text{ }\mathbf{48}\] Here, \[\mathbf{initial}\text{...
Shamshad Ali buys a scooter for Rs 22000. He pays Rs 4000 cash and agrees to pay the balance in annual installment of Rs 1000 plus 10% interest on the unpaid amount. How much will the scooter cost him?
Given, Shamshad Ali purchases a bike for Rs 22000 and pays Rs 4000 in real money. Thus, the neglected sum \[=\text{ }\mathbf{Rs}\text{ }\mathbf{22000}\text{ }\text{ }\mathbf{Rs}\text{...
A farmer buys a used tractor for Rs 12000. He pays Rs 6000 cash and agrees to pay the balance in annual installments of Rs 500 plus 12% interest on the unpaid amount. How much will be the tractor cost him?
Given, the rancher pays Rs 6000 in real money. In this way, the neglected sum \[=\text{ }\mathbf{Rs}\text{ }\mathbf{12000}\text{ }\text{ }\mathbf{Rs}\text{ }\mathbf{6000}\text{ }=\text{...
Show that:
nth term of the numerator \[=~n{{\left( n~+\text{ }1 \right)}^{2}}~\] \[=~{{n}^{3}}~+\text{ }2{{n}^{2}}~+\text{ }n\] and the nth term of the denominator \[=~{{n}^{2}}\left( n~+\text{ }1 \right)\]...
Find the sum of the following series up to n terms:
solution:
If S1, S2, S3 are the sum of first n natural numbers, their squares and their cubes, respectively, show that 9S22 = S3 (1 + 8S1).
As the question says, we have In this way, from (1) and (2), we have \[\mathbf{9S22}\text{ }=\text{ }\mathbf{S3}\text{ }\left( \mathbf{1}\text{ }+\text{ }\mathbf{8S1} \right).\]
Find the sum of the first n terms of the series: 3 + 7 + 13 + 21 + 31 + …
The given series is \[\mathbf{3}\text{ }+\text{ }\mathbf{7}\text{ }+\text{ }\mathbf{13}\text{ }+\text{ }\mathbf{21}\text{ }+\text{ }\mathbf{31}\text{ }+\text{ }\ldots \] \[\mathbf{S}\text{ }=\text{...
Find the 20th term of the series 2 × 4 + 4 × 6 + 6 × 8 + … + n terms.
Given series is \[\mathbf{2}\text{ }\times \text{ }\mathbf{4}\text{ }+\text{ }\mathbf{4}\text{ }\times \text{ }\mathbf{6}\text{ }+\text{ }\mathbf{6}\text{ }\times \text{ }\mathbf{8}\text{ }+\text{...
Find the sum of the following series up to n terms: (i) 5 + 55 + 555 + … (ii) .6 + .66 + . 666 + …
(i) Given, \[\mathbf{5}\text{ }+\text{ }\mathbf{55}\text{ }+\text{ }\mathbf{555}\text{ }+\text{ }\ldots \] Let \[\mathbf{Sn}\text{ }=\text{ }\mathbf{5}\text{ }+\text{ }\mathbf{55}\text{ }+\text{...
If a, b, c are in A.P,; b, c, d are in G.P and 1/c, 1/d, 1/e are in A.P. prove that a, c, e are in G.P.
Given a, b, c are in A.P. Thus, \[\mathbf{b}\text{ }\text{ }\mathbf{a}\text{ }=\text{ }\mathbf{c}\text{ }\text{ }\mathbf{b}\text{ }\ldots \text{ }\left( \mathbf{1} \right)\] What's more,...
The ratio of the A.M and G.M. of two positive numbers a and b, is m: n. Show that
Leave the two numbers alone an and b. \[A.M\text{ }=\text{ }\left( a\text{ }+\text{ }b \right)/2\text{ }and\text{ }G.M.\text{ }=\text{ }\surd ab\] From the inquiry, we have
If a and b are the roots of x2 – 3x + p = 0 and c, dare roots of x2 – 12x + q = 0, where a, b, c, d, form a G.P. Prove that (q + p): (q – p) = 17:15
Given, an and b are the foundations of \[\mathbf{x2}\text{ }\text{ }\mathbf{3x}\text{ }+\text{ }\mathbf{p}\text{ }=\text{ }\mathbf{0}\] Along these lines, we have \[\mathbf{a}\text{ }+\text{...
If a, b, c, d are in G.P, prove that (an + bn), (bn + cn), (cn + dn) are in G.P.
Given, a, b, c,and d are in G.P. Along these lines, we have \[\therefore \mathbf{b2}\text{ }=\text{ }\mathbf{ac}\text{ }\ldots \text{ }\left( \mathbf{I} \right)\] \[\mathbf{c2}\text{ }=\text{...
prove that a, b, c are in A.P.
If are in A.P
The pth, qth and rth terms of an A.P. are a, b, c respectively. Show that (q – r) a + (r – p) b + (p -q) c = 0
We should expect t and d to be the initial term and the normal distinction of the A.P. individually. Then, at that point, the nth term of the A.P. is given by, \[\mathbf{a}\text{ }=\text{...
Let S be the sum, P the product and R the sum of reciprocals of n terms in a G.P. Prove that \[{{\mathbf{P}}^{\mathbf{2}}}{{\mathbf{R}}^{n}}^{~}=\text{ }{{\mathbf{S}}^{n}}\]
Give the terms access G.P. be \[\mathbf{a},\text{ }\mathbf{ar},\text{ }\mathbf{ar2},\text{ }\mathbf{ar3},\text{ }\ldots \text{ }\mathbf{arn}\text{ }\text{ }\mathbf{1}\ldots \] Structure the inquiry,...
show that a, b, c and d are in G.P.
Given, On cross duplicating, we have Likewise, given On cross duplicating, we have From (1) and (2), we get \[\mathbf{b}/\mathbf{a}\text{ }=\text{ }\mathbf{c}/\mathbf{b}\text{ }=\text{...
The sum of the first four terms of an A.P. is 56. The sum of the last four terms is 112. If its first term is 11, then find the number of terms
How about we think about the terms in A.P. to be \[\mathbf{a},\text{ }\mathbf{a}\text{ }+\text{ }\mathbf{d},\text{ }\mathbf{a}\text{ }+\text{ }\mathbf{2d},\text{ }\mathbf{a}\text{ }+\text{...
A G.P. consists of an even number of terms. If the sum of all the terms is 5 times the sum of terms occupying odd places, then find its common ratio.
We should consider the terms in the G.P.to be \[\mathbf{T1},\text{ }\mathbf{T2},\text{ }\mathbf{T3},\text{ }\mathbf{T4},\text{ }\ldots \text{ }\mathbf{T2n}.\] The quantity of terms \[=\text{...
The sum of three numbers in G.P. is 56. If we subtract 1, 7, 21 from these numbers in that order, we obtain an arithmetic progression. Find the numbers.
How about we think about the three numbers in G.P. to be as \[\mathbf{a},\text{ }\mathbf{ar},\text{ }\mathbf{and}\text{ }\mathbf{ar2}.\] Then, at that point, from the inquiry, we have...
The first term of a G.P. is 1. The sum of the third term and fifth term is 90. Find the common ratio of G.P.
How about we consider an and r to be the initial term and the normal proportion of the G.P. separately. Given, \[\mathbf{a}\text{ }=\text{ }\mathbf{1}\] \[\mathbf{a3}\text{ }=\text{...
The sum of some terms of G.P. is 315 whose first term and the common ratio are 5 and 2, respectively. Find the last term and the number of terms
Considering that the amount of certain terms in a G.P is \[\mathbf{315}.\] Leave the quantity of terms alone n. We realize that, amount of terms is Considering that the initial term an is...
If f is a function satisfying f(x + y) = f(x) f(y) for all x, y ∈ N and find the value of n.
Considering that, \[\mathbf{f}\text{ }\left( \mathbf{x}\text{ }+\text{ }\mathbf{y} \right)\text{ }=\text{ }\mathbf{f}\text{ }\left( \mathbf{x} \right)\text{ }\times \text{ }\mathbf{f}\text{ }\left(...
The difference between any two consecutive interior angles of a polygon is 5°. If the smallest angle is 120°, find the number of the sides of the polygon.
It's perceived from the inquiry that, the points of the polygon will frame an A.P. with normal contrast \[d\text{ }=\text{ }5{}^\circ \text{ }and\text{ }initial\text{ }term\text{ }a\text{ }=\text{...
A man starts repaying a loan as first instalment of Rs. 100. If he increases the instalment by Rs 5 every month, what amount he will pay in the 30th instalment?
Given, The primary portion of the advance is \[Rs\text{ }100.\] The second portion of the credit is \[Rs\text{ }105,\]etc as the portion increments by \[Rs\text{ }5\]consistently. In this way, the...
Between 1 and 31, m numbers have been inserted in such a way that the resulting sequence is an A.P. and the ratio of 7th and (m – 1)th numbers is 5: 9. Find the value of m.
How about we consider \[{{a}_{1}},\text{ }{{a}_{2}},\text{ }\ldots \text{ }{{a}_{m}}~be~m\]numbers to such an extent that \[1,\text{ }{{a}_{1}},\text{ }{{a}_{2}},\text{ }\ldots \text{...
If fig given below is the A.M. between a and b, then find the value of n.
Solution:- The A.M among \[a\text{ }and\text{ }b\]is given by, \[\left( a\text{ }+\text{ }b \right)/2\] Then, at that point, as indicated by the inquiry, Along these lines, the worth of \[n\text{...
Find the sum of all two digit numbers which when divided by 4, yields 1 as remainder
We need to initially track down the two-digit numbers, which when partitioned by 4, yield 1 as remaining portion. They are: \[\mathbf{13},\text{ }\mathbf{17},\text{ }\ldots \text{...
Insert five numbers between 8 and 26 such that the resulting sequence is an A.P.
We should expect\[{{A}_{1}},\text{ }{{A}_{2}},\text{ }{{A}_{3}},\text{ }{{A}_{4}},\text{ }and\text{ }{{A}_{5}}\] to be five numbers between \[8\text{ }and\text{ }26~\]with the end goal that...
If the sum of n terms of an A.P. is 3n^2 + 5n and its mth term is 164, find the value of m.
How about we take \[a\text{ }and\text{ }d\]to be the initial term and the normal contrast of the A.P. separately. \[{{a}_{m}}~=~a~+\text{ }(m~\text{ }1)d~=\text{ }164\text{ }\ldots \text{ }\left( 1...
The ratio of the sums of m and n terms of an A.P. is m^2: n^2. Show that the ratio of mth and nth term is (2m – 1): (2n – 1).
How about we take \[a\text{ }and\text{ }d\]to be the initial term and the normal contrast of the A.P. separately. Then, at that point, it given that Hence, the given result is proved.
Sum of the first p, q and r terms of an A.P. are a, b and c, respectively. Prove that
Solution:- How about we take \[a\text{ }and\text{ }d\]to be the initial term and the normal contrast of the A.P. separately. Then, at that point, it given that
If the sum of first p terms of an A.P. is equal to the sum of the first q terms, then find the sum of the first (p + q) terms.
How about we take \[a\text{ }and\text{ }d\]to be the initial term and the normal contrast of the A.P. separately. Then, at that point, it given that Along these lines, the amount of \[\left( p\text{...
The sums of n terms of two arithmetic progressions are in the ratio 5n + 4: 9n + 6. Find the ratio of their 18th terms.
Let \[a1,\text{ }a2,\text{ }and\text{ }d1,\text{ }d2\]be the initial terms and the normal distinction of the first and second math movement individually. Then, at that point, from the inquiry we...
Find the sum of integers from 1 to 100 that are divisible by 2 or 5
First how about we discover the whole numbers from\[\mathbf{1}\text{ }\mathbf{to}\text{ }\mathbf{100}\] , which are distinguishable by 2. What's more, they are\[\mathbf{2},\text{ }\mathbf{4},\text{...
If the sum of n terms of an A.P. is (pn + qn2), where p and q are constants, find the common difference.
We realize that, \[{{S}_{n}}~=\text{ }n/2\text{ }\left[ 2a\text{ }+\text{ }\left( n-1 \right)d \right]\] From the inquiry we have, On looking at the coefficients of\[{{n}^{2}}\] on the two sides, we...
Find the sum to n terms of the A.P., whose kth term is 5k + 1.
Given, the \[{{k}^{th}}~\]term of the A.P. is . \[5k~+\text{ }1.\] \[{{k}^{th}}~term\text{ }=~{{a}_{k}}~=~a~+\text{ }(k~\text{ }1)d\] And, \[\begin{array}{*{35}{l}} a~+\text{ }\left( k~\text{ }1...
If the sum of a certain number of terms of the A.P. 25, 22, 19, … is 116. Find the last term
Given A.P., \[25,\text{ }22,\text{ }19,\text{ }\ldots \] Here, Initial term, \[a\text{ }=\text{ }25\]and Normal distinction, \[d\text{ }=\text{ }22\text{ }\text{ }25\text{ }=\text{ }-\text{ }3\]...
In an A.P., if pth term is 1/q and qth term is 1/p, prove that the sum of first pq terms is ½ (pq + 1) where p ≠ q.
Solution:-
Find the sum of all numbers between 200 and 400 which are divisible by 7
First how about we discover the numbers somewhere in the range of \[\mathbf{200}\text{ }\mathbf{and}\text{ }\mathbf{400}\] which are detachable by \[\mathbf{7}.\] The numbers are:...
How many terms of the A.P. -6, -11/2, -5, …. are needed to give the sum –25?
How about we consider the amount of n terms of the given A.P. as \[\text{ }25.\] We realized that, \[{{S}_{n}}~=\text{ }n/2\text{ }\left[ 2a\text{ }+\text{ }\left( n-1 \right)d \right]\] where...
In an A.P, the first term is 2 and the sum of the first five terms is one-fourth of the next five terms. Show that 20th term is –112.
Given, The initial term \[\left( a \right)\]of an \[A.P\text{ }=\text{ }2\] How about we accept d be the normal contrast of the A.P. In this way, the A.P. will be \[2,\text{ }2\text{ }+\text{...
Let the sum of n, 2n, 3n terms of an A.P. be S1, S2 and S3, respectively, show that S3 = 3 (S2– S1)
We should take an and d to be the initial term and the normal distinction of the A.P. individually. Thus, we have
Find the sum of all natural numbers lying between 100 and 1000, which are multiples of 5.
The regular numbers lying somewhere in the range of \[100\text{ }and\text{ }1000,\]which are products of \[5,\text{ }are\text{ }105,\text{ }110,\text{ }\ldots \text{ }995.\] It plainly frames an...
Find the sum of odd integers from 1 to 2001.
The odd numbers from \[1\text{ }to\text{ }2001\]are\[~1,\text{ }3,\text{ }5,\text{ }\ldots \text{ }1999,\text{ }2001.\] It obviously shapes an arrangement in \[A.P.\] Where, the initial term,...
The Fibonacci sequence is defined by \[\mathbf{1}\text{ }=\text{ }{{\mathbf{a}}_{\mathbf{1}}}~=\text{ }{{\mathbf{a}}_{\mathbf{2}}}~\mathbf{and}\text{ }{{\mathbf{a}}_{\mathbf{n}}}~=\text{ }{{\mathbf{a}}_{\mathbf{n}\text{ }\text{ }\mathbf{1}~}}+\text{ }{{\mathbf{a}}_{\mathbf{n}\text{ }\text{ }\mathbf{2}}},\text{ }\mathbf{n}\text{ }>\text{ }\mathbf{2}\]. Find \[{{\mathbf{a}}_{\mathbf{n}+\mathbf{1}}}/{{\mathbf{a}}_{\mathbf{n}}},\text{ }\mathbf{for}\text{ }\mathbf{n}\text{ }=\text{ }\mathbf{1},\text{ }\mathbf{2},\text{ }\mathbf{3},\text{ }\mathbf{4},\text{ }\mathbf{5}~\]
Given, \[\begin{array}{*{35}{l}} 1\text{ }=\text{ }{{a}_{1}}~=\text{ }{{a}_{2}} \\ {{a}_{n}}~=\text{ }{{a}_{n\text{ }\text{ }1~}}+\text{ }{{a}_{n\text{ }\text{ }2}},\text{ }n\text{ }>\text{ }2 ...
If the sum of three numbers in A.P., is 24 and their product is 440, find the numbers
We should think about the three numbers in A.P. as \[\mathbf{a}\text{ }\text{ }\mathbf{d},\text{ }\mathbf{a},\text{ }\mathbf{and}\text{ }\mathbf{a}\text{ }+\text{ }\mathbf{d}.\] Then, at that point,...
Write the first five terms of each of the sequences and obtain the corresponding series: \[~{{\mathbf{a}}_{\mathbf{1}}}~=\text{ }{{\mathbf{a}}_{\mathbf{2}~}}=\text{ }\mathbf{2},\text{ }{{\mathbf{a}}_{\mathbf{n}}}~=\text{ }{{\mathbf{a}}_{\mathbf{n}-\mathbf{1}}}~\text{ }\mathbf{1},\text{ }\mathbf{n}\text{ }>\text{ }\mathbf{2}\]
Given, \[{{a}_{1}}~=\text{ }{{a}_{2}},\text{ }{{a}_{n}}~=\text{ }{{a}_{n-1}}~\text{ }1\] Then, at that point, \[\begin{array}{*{35}{l}} {{a}_{3}}~=\text{ }{{a}_{2}}~\text{ }1\text{ }=\text{ }2\text{...
Show that the sum of (m + n)th and (m – n)th terms of an A.P. is equal to twice the mth term.
How about we take an and d to be the initial term and the normal distinction of the A.P. individually. We realize that, the kth term of A. P. is given by \[\mathbf{ak}\text{ }=\text{...
Write the first five terms of each of the sequences and obtain the corresponding series: \[~{{\mathbf{a}}_{\mathbf{1}}}~=\text{ }-\mathbf{1},\text{ }{{\mathbf{a}}_{\mathbf{n}}}~=\text{ }{{\mathbf{a}}_{\mathbf{n}-\mathbf{1}}}/\mathbf{n},\text{ }\mathbf{n}\text{ }\ge \text{ }\mathbf{2}\]
Given, \[{{a}_{n}}~=\text{ }{{a}_{n-1}}/n\text{ }and\text{ }{{a}_{1}}~=\text{ }-1\] Then, at that point, \[\begin{array}{*{35}{l}} {{a}_{2}}~=\text{ }{{a}_{1}}/2\text{ }=\text{ }-1/2 \\...
Find the sum to n terms of the series whose nth terms is given by (2n – 1)2
Given, nth term of the series as: \[\mathbf{a}\text{ }=\text{ }\left( \mathbf{2n}\text{ }\text{ }\mathbf{1} \right)\mathbf{2}\text{ }=\text{ }\mathbf{4n2}\text{ }\text{ }\mathbf{4n}\text{ }+\text{...
Write the first five terms of each of the sequences and obtain the corresponding series: \[~{{\mathbf{a}}_{\mathbf{1}}}~=\text{ }\mathbf{3},\text{ }{{\mathbf{a}}_{\mathbf{n}}}~=\text{ }\mathbf{3}{{\mathbf{a}}_{\mathbf{n}-\mathbf{1}}}~+\text{ }\mathbf{2}\text{ }\mathbf{for}\text{ }\mathbf{all}\text{ }\mathbf{n}\text{ }>\text{ }\mathbf{1}\]
Given, \[{{a}_{n}}~=\text{ }3{{a}_{n-1}}~+\text{ }2\text{ }and\text{ }{{a}_{1}}~=\text{ }3\] Then, at that point, \[\begin{array}{*{35}{l}} {{a}_{2}}~=\text{ }3{{a}_{1}}~+\text{ }2\text{ }=\text{...
Find the indicated terms in each of the sequences whose nth terms are
Solution:- On substituting\[n~=\text{ 20}\], we get
Find the sum to n terms of the series whose nth terms is given by n2 + 2n
Given, nth term of the series as: \[\mathbf{a}\text{ }=\text{ }\mathbf{n2}\text{ }+\text{ }\mathbf{2n}\] Then, at that point, the amount of n terms of the series can be communicated as
Find the indicated terms in each of the sequences whose nth terms are: \[{{\mathbf{a}}_{\mathbf{n}}}~=\text{ }{{\left( -\mathbf{1} \right)}^{\mathbf{n}-\mathbf{1}}}~{{\mathbf{n}}^{\mathbf{3}}};\text{ }{{\mathbf{a}}_{\mathbf{9}}}\]
Given, \[{{n}^{th}}~\]term of the grouping is \[{{a}_{n}}~=\text{ }{{\left( -1 \right)}^{n-1}}~{{n}^{3}}\] On substituting\[n~=\text{ }9\], we get \[{{a}_{9}}~=\text{ }{{\left( -1...
Find the sum to n terms of the series whose nth term is given by n (n + 1) (n + 4).
Given, \[\mathbf{a}\text{ }=\text{ }\left( \mathbf{n}\text{ }+\text{ }\mathbf{1} \right)\text{ }\left( \mathbf{n}\text{ }+\text{ }\mathbf{4} \right)\text{ }=\text{ }\mathbf{n}\left(...
Find the sum to n terms of the series 12 + (12 + 22) + (12 + 22 + 32) + …
Given series is \[\mathbf{12}\text{ }+\text{ }\left( \mathbf{12}\text{ }+\text{ }\mathbf{22} \right)\text{ }+\text{ }\left( \mathbf{12}\text{ }+\text{ }\mathbf{22}\text{ }+\text{ }\mathbf{32}\text{...
Find the indicated terms in each of the sequences whose nth terms are: \[{{\mathbf{a}}_{\mathbf{n}}}~=~{{\mathbf{n}}^{\mathbf{2}}}/{{\mathbf{2}}^{\mathbf{n}}}~;~{{\mathbf{a}}^{\mathbf{7}}}\]
Given, \[{{n}^{th}}\]term of the grouping is \[{{a}_{n}}~=\text{ }{{n}^{2}}/{{2}^{n}}\] Presently, on substituting\[~n~=\text{ }7\], we get \[{{a}_{7}}~=\text{ }{{7}^{2}}/{{2}^{7}}~=\text{...
Find the sum to n terms of the series 3 × 8 + 6 × 11 + 9 × 14 +…
Given series is \[\mathbf{3}\text{ }\times \text{ }\mathbf{8}\text{ }+\text{ }\mathbf{6}\text{ }\times \text{ }\mathbf{11}\text{ }+\text{ }\mathbf{9}\text{ }\times \text{ }\mathbf{14}\text{ }+\text{...
Find the sum to n terms of the series 52 + 62 + 72 + … + 202
Given series is \[\mathbf{52}\text{ }+\text{ }\mathbf{62}\text{ }+\text{ }\mathbf{72}\text{ }+\text{ }\ldots \text{ }+\text{ }\mathbf{202}\] It's seen that, nth term, \[\mathbf{a}\text{ }=\text{...
Find the sum to n terms of the series:
Find the sum to n terms of the series: 3 × 12 + 5 × 22 + 7 × 32 + …
Given series is \[\mathbf{3}\text{ }\times \mathbf{12}\text{ }+\text{ }\mathbf{5}\text{ }\times \text{ }\mathbf{22}\text{ }+\text{ }\mathbf{7}\text{ }\times \text{ }\mathbf{32}\text{ }+\text{...
Find the sum to n terms of the series: 1 × 2 × 3 + 2 × 3 × 4 + 3 × 4 × 5 + …
Given series is \[\mathbf{1}\text{ }\times \text{ }\mathbf{2}\text{ }\times \text{ }\mathbf{3}\text{ }+\text{ }\mathbf{2}\text{ }\times \text{ }\mathbf{3}\text{ }\times \text{ }\mathbf{4}\text{...
Find the sum to n terms of the series: 1 × 2 + 2 × 3 + 3 × 4 + 4 × 5 + …
Given series is \[1\text{ }\times \text{ }2\text{ }+\text{ }2\text{ }\times \text{ }3\text{ }+\text{ }3\text{ }\times \text{ }4\text{ }+\text{ }4\text{ }\times \text{ }5\text{ }+\text{ }\ldots \]...
Find the sum to n terms of the A.P., whose kth term is 5k + 1.
Given, the \[{{k}^{th}}\]term of the A.P. is \[5k~+\text{ }1.\] \[{{k}^{th}}~term\text{ }=~{{a}_{k}}~=~a~+\text{ }(k~\text{ }1)d\] Also, \[\begin{array}{*{35}{l}} a~+\text{ }\left( k~\text{ }1...
If the sum of a certain number of terms of the A.P. 25, 22, 19, … is 116. Find the last term
Given A.P., \[25,\text{ }22,\text{ }19,\text{ }\ldots \] Here, Initial term, \[a\text{ }=\text{ }25\]and Normal distinction, \[d\text{ }=\text{ }22\text{ }\text{ }25\text{ }=\text{ }-\text{ }3\]...
In an A.P., if pth term is 1/q and qth term is 1/p, prove that the sum of first pq terms is ½ (pq + 1) where p ≠ q.
Solution:-
How many terms of the A.P. -6, -11/2, -5, …. are needed to give the sum –25?
How about we consider the amount of \[n\]terms of the given A.P. as \[\text{ }25.\] We realized that, \[{{S}_{n}}~=\text{ }n/2\text{ }\left[ 2a\text{ }+\text{ }\left( n-1 \right)d \right]\]...
In an A.P, the first term is 2 and the sum of the first five terms is one-fourth of the next five terms. Show that 20th term is –112.
Given, The initial term \[\left( a \right)\]of an A.P \[=\text{ }2\] How about we accept d be the normal distinction of the A.P. In this way, the A.P. will be \[2,\text{ }2\text{ }+\text{ }d,\text{...
Find the sum of all natural numbers lying between 100 and 1000, which are multiples of 5.
The normal numbers lying somewhere in the range of\[100\text{ }and\text{ }1000\], which are products of \[5,\text{ }are\text{ }105,\text{ }110,\text{ }\ldots \text{ }995.\] It unmistakably frames a...
Find the sum of odd integers from 1 to 2001.
The odd whole numbers from \[1\text{ }to\text{ }2001\text{ }are\text{ }1,\text{ }3,\text{ }5,\text{ }\ldots \text{ }1999,\text{ }2001.\] It unmistakably frames a succession in A.P. Where, the...
If A.M. and G.M. of roots of a quadratic equation are 8 and 5, respectively, then obtain the quadratic equation.
We should consider the underlying foundations of the quadratic condition to be \[a~and~b.\] Then, at that point, we have We realize that, A quadratic condition can be framed as, \[\begin{align}...
What will Rs 500 amounts to in 10 years after its deposit in a bank which pays annual interest rate of 10% compounded annually?
Given, The sum saved in the bank is \[Rs\text{ }500.\] Toward the finish of \[~first\text{ }year,\text{ }amount\]\[=\text{ }Rs\text{ }500\left( 1\text{ }+\text{ }1/10 \right)~=\text{ }Rs\text{...
The number of bacteria in a certain culture doubles every hour. If there were 30 bacteria present in the culture originally, how many bacteria will be present at the end of 2nd hour, 4th hour and nth hour?
Given, the quantity of bacteria copies each hour. Henceforth, the quantity of bacteria after consistently will frame a G.P. Here we have, \[a\text{ }=\text{ }30\text{ }and\text{ }r\text{ }=\text{...
If A and G be A.M. and G.M., respectively between two positive numbers, prove that the numbers are positive.
Solution:- Considering that \[A\text{ }and\text{ }G\]are A.M. furthermore, G.M. between two positive numbers. Furthermore, let these two positive numbers be\[a\text{ }and\text{ }b\].
The sum of two numbers is 6 times their geometric mean, show that numbers are in the ratio
Solution:- Consider the two numbers be\[a\text{ }and\text{ }b\]. Then, at that point, \[G.M.\text{ }=\text{ }\surd ab.\] From the inquiry, we have
Find the value of n in the fig. given so that may be the geometric mean between a and b.
Solution:- We realize that, The G. M. of \[a\text{ }and\text{ }b\]is given by \[\surd ab.\] Then, at that point, from the inquiry, we have By squaring both sides, we get Performing cross increase in...
Insert two numbers between 3 and 81 so that the resulting sequence is G.P.
How about we accept \[{{G}_{1}}~and~{{G}_{2}}\]to be two numbers somewhere in the range of \[3\text{ }and\text{ }81\]with the end goal that the series \[3,~{{G}_{1}},~{{G}_{2}},\text{ }81~\]frames a...
If a, b, c and d are in G.P. show that (a2 + b2 + c2)(b2 + c2 + d2) = (ab + bc + cd)2.
Given, \[~a,~b,~c,~d~\]are in G.P. Thus, we have \[\begin{array}{*{35}{l}} bc~=~ad~\text{ }\ldots \text{ }\left( 1 \right) \\ {{b}^{2}}~=~ac~~\ldots \text{ }\left( 2 \right) \\...
Show that the ratio of the sum of first n terms of a G.P. to the sum of terms from
SOLUTION:- Let \[a\]be the initial term and \[r\]be the normal proportion of the G.P. Since there are n terms from \[~{{(n~+1)}^{th}}~to\text{ }{{(2n)}^{th}}~term,\] Amount of terms from...
If the first and the nth term of a G.P. are a ad b, respectively, and if P is the product of n terms, prove that P2 = (ab)n.
Given, the initial term of the G.P is an and the last term is \[b.\] Hence, The G.P. \[~a,~ar,~a{{r}^{2}},~a{{r}^{3}},\text{ }\ldots ~a{{r}^{n}}^{1},\]is the place where r is the normal proportion....
If the pth, qth and rth terms of a G.P. are a, b and c, respectively. Prove that aq-r br-p cp-q = 1
We should take \[A\]to be the initial term and \[R\]to be the normal proportion of the G.P. Then, at that point, as per the inquiry, we have \[\begin{array}{*{35}{l}} A{{R}^{p}}^{1~}=~a \\...
Find four numbers forming a geometric progression in which third term is greater than the first term by 9, and the second term is greater than the 4th by 18.
Consider \[a\]to be the initial term and \[r\]to be the normal proportion of the G.P. Then, at that point, \[{{a}_{1}}~=~a,~{{a}_{2}}~=~ar,~{{a}_{3}}~=~a{{r}^{2}},~{{a}_{4}}~=~a{{r}^{3}}\] From the...
Show that the products of the corresponding terms of the sequences a, ar, ar2, …arn-1 and A, AR, AR2, … ARn-1 form a G.P, and find the common ratio.
To be demonstrated: The grouping, \[aA,~arAR,~a{{r}^{2}}A{{R}^{2}},\text{ }\ldots a{{r}^{n}}^{1}A{{R}^{n}}^{1}\] shapes a G.P. Presently, we have In this way, the above arrangement frames a G.P....
Find the sum of the products of the corresponding terms of the sequences 2, 4, 8, 16, 32 and 128, 32, 8, 2, 1/2.
The necessary aggregate \[=~2\text{ }x\text{ }128\text{ }+\text{ }4\text{ }x\text{ }32\text{ }+\text{ }8\text{ }x\text{ }8\text{ }+\text{ }16\text{ }x\text{ }2\text{ }+\text{ }32\text{ }x\text{...
Find the sum to n terms of the sequence, 8, 88, 888, 8888…
Given arrangement: \[8,\text{ }88,\text{ }888,\text{ }8888\ldots \] This arrangement isn't a G.P. In any case, it tends to be changed to G.P. by composing the terms as \[{{S}_{n}}~=\text{ }8\text{...
If the 4th, 10th and 16th terms of a G.P. are x, y and z, respectively. Prove that x, y, z are in G.P.
Let \[a\]be the initial term and\[~r\] be the normal proportion of the G.P. As per the given condition, \[\begin{array}{*{35}{l}} {{a}_{4}}~=~a~{{r}^{3}}~=~x~\ldots \text{ }\left( 1 \right) \\...
Find a G.P. for which sum of the first two terms is –4 and the fifth term is 4 times the third term.
Consider \[a\]to be the initial term and r to be the normal proportion of the G.P. Given, \[{{S}_{2}}~=\text{ }-4\] Then, at that point, from the inquiry we have Also, \[\begin{array}{*{35}{l}}...
Given a G.P. with a = 729 and 7th term 64, determine S7.
Given, \[a~=\text{ }729\text{ }and~{{a}_{7}}~=\text{ }64\] Leave \[r\]alone the normal proportion of the G.P. Then, at that point, we realize that, \[{{a}_{n}}~=~a\text{ }{{r}^{n}}^{1}\]...
The sum of first three terms of a G.P. is 16 and the sum of the next three terms is 128. Determine the first term, the common ratio and the sum to n terms of the G.P.
We should accept the G.P. to be \[a,~ar,~a{{r}^{2}},~a{{r}^{3}},\text{ }\ldots \] Then, at that point, as per the inquiry, we have \[\begin{array}{*{35}{l}} a~+~ar~+~a{{r}^{2}}~=\text{ }16\text{...
How many terms of G.P. 3, 32, 33, … are needed to give the sum 120?
Given G.P. is How about we consider that \[n\]terms of this G.P. be needed to acquire the amount of \[120.\] We realize that, Here, \[a\text{ }=\text{ }3\text{ }and\text{ }r\text{ }=\text{ }3\]...
The sum of first three terms of a G.P. is 39/10 and their product is 1. Find the common ratio and the terms.
Let \[a/r,\text{ }a,\text{ }ar\]be the initial three terms of the \[G.P.\] \[\begin{array}{*{35}{l}} a/r\text{ }+\text{ }a\text{ }+\text{ }ar\text{ }=\text{ }39/10\text{ }\ldots \ldots \text{...
Evaluate given the equation:
SOLUTION:-
Find the sum to n terms in the geometric progression x3, x5, x7, … (if x ≠ ±1 )
Given G.P. is \[{{x}^{3}},\text{ }{{x}^{5}},\text{ }{{x}^{7}},\text{ }\ldots \] Here, we have \[a~=~{{x}^{3}}~and~r~=~{{x}^{5}}/{{x}^{3}}~=\text{ }{{x}^{2}}\]
Find the sum to n terms in the geometric progression 1, -a, a2, -a3 …. (if a ≠ -1)
The given G.P. is \[1,\text{ }-\text{ }a,\text{ }a2,\text{ }-\text{ }a3\text{ }\ldots \text{ }.\] Here, the initial term \[=\text{ }a1\text{ }=\text{ }1\] Furthermore, the normal proportion...
Find the sum to n terms in the geometric progression √7, √21, 3√7, ….
The given G.P is \[\surd 7,\text{ }\surd 21,\text{ }3\surd 7,\text{ }\ldots \text{ }.\] Here, \[a\text{ }=\text{ }\surd 7\]and
Find the sum to 20 terms in the geometric progression 0.15, 0.015, 0.0015 …
Given \[G.P.,\text{ }0.15,\text{ }0.015,\text{ }0.00015,\text{ }\ldots \] Here, \[a\text{ }=\text{ }0.15\text{ }and\text{ }r\text{ }=\text{ }0.015/0.15\text{ }=\text{ }0.1\]
For what values of x, the numbers -2/7, x, -7/2 are in G.P?
The given numbers are \[-\text{ }2/7,\text{ }x,\text{ }-\text{ }7/2.\] Normal proportion \[=\text{ }x/\left( -\text{ }2/7 \right)\text{ }=\text{ }-\text{ }7x/2\] Additionally, normal proportion...
Which term of the following sequences: 1/3, 1/9, 1/27, … is 1/19683 ?
Given arrangement, \[1/3,\text{ }1/9,\text{ }1/27,\text{ }\ldots \] \[a\text{ }=\text{ }1/3\text{ }and\text{ }r\text{ }=\text{ }\left( 1/9 \right)/\left( 1/3 \right)\text{ }=\text{ }1/3\] Taking the...
Which term of the following sequences: (a) 2, 2√2, 4,… is 128 ? (b) √3, 3, 3√3,… is 729 ?
(i) The given arrangement, \[2,\text{ }2\surd 2,\text{ }4,\ldots \] We have, \[a\text{ }=\text{ }2\text{ }and\text{ }r\text{ }=\text{ }2\surd 2/2\text{ }=\text{ }\surd 2\] Taking the...
The 4th term of a G.P. is square of its second term, and the first term is –3. Determine its 7th term
We should consider \[a\]to be the initial term and \[r\]to be the normal proportion of the \[G.P.\] Given, \[a\text{ }=\text{ }\text{ }3\] Also, we realize that, \[\begin{align} &...
The 5th, 8th and 11th terms of a G.P. are p, q and s, respectively. Show that q2 = ps.
How about we take \[a\]to be the initial term and \[r\]to be the normal proportion of the G.P. Then, at that point, as indicated by the inquiry, we have \[\begin{array}{*{35}{l}}...
Find the 12th term of a G.P. whose 8th term is 192 and the common ratio is 2.
Given, The normal proportion of the G.P., \[r\text{ }=\text{ }2\] What's more, let\[~a\] be the initial term of the G.P. Presently, \[\begin{array}{*{35}{l}} {{a}_{8}}~=~ar{{~}^{81}}~=~a{{r}^{7}} ...
Find the 20th and nth terms of the G.P. 5/2, 5/4, 5/8, ………
Given G.P. is \[5/2,\text{ }5/4,\text{ }5/8,\ldots \ldots \] Here, \[a\text{ }=\text{ }First\text{ }term\text{ }=\text{ }5/2\] \[r\text{ }=\text{ }Common\text{ }proportion\text{ }=\text{ }\left( 5/4...