Ratio and Proportion

If \[(\mathbf{3}{{\mathbf{x}}^{\mathbf{2}}}~+\text{ }\mathbf{2}{{\mathbf{y}}^{\mathbf{2}}}):\text{ }(\mathbf{3}{{\mathbf{x}}^{\mathbf{2}}}~\text{ }\mathbf{2}{{\mathbf{y}}^{\mathbf{2}}})\text{ }=\text{ }\mathbf{11}:\text{ }\mathbf{9}\], find the value of \[\frac{3{{x}^{4}}+25{{y}^{4}}}{3{{x}^{4}}-25{{y}^{4}}}\]

It is given that \[(\mathbf{3}{{\mathbf{x}}^{\mathbf{2}}}~+\text{ }\mathbf{2}{{\mathbf{y}}^{\mathbf{2}}}):\text{ }(\mathbf{3}{{\mathbf{x}}^{\mathbf{2}}}~\text{...

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If \[\left( \mathbf{a}\text{ }+\text{ }\mathbf{2b}\text{ }+\text{ }\mathbf{c} \right),\text{ }\left( \mathbf{a}\text{ }\text{ }\mathbf{c} \right)\text{ }\mathbf{and}\text{ }\left( \mathbf{a}\text{ }\text{ }\mathbf{2b}\text{ }+\text{ }\mathbf{c} \right)\] are in continued proportion, prove that b is the mean proportional between a and c.

It is given that \[\left( \mathbf{a}\text{ }+\text{ }\mathbf{2b}\text{ }+\text{ }\mathbf{c} \right),\text{ }\left( \mathbf{a}\text{ }\text{ }\mathbf{c} \right)\text{ }\mathbf{and}\text{ }\left(...

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In an examination, the number of those who passed and the number of those who failed were in the ratio of \[3:1\]. Had \[8\] more appeared, and \[6\] less passed, the ratio of passed to failures would have been \[2:1\]. Find the number of candidates who appeared.

Consider the number of passed = \[3x\] Number of failed = x So the total candidates appeared = \[3x\text{ }+\text{ }x\text{ }=\text{ }4x\] In the second case Number of candidates appeared =...

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Find the compound ratio of \[{{\left( \mathbf{a}\text{ }+\text{ }\mathbf{b} \right)}^{\mathbf{2}}}:\text{ }{{\left( \mathbf{a}\text{ }\text{ }\mathbf{b} \right)}^{\mathbf{2}}},\text{ }({{\mathbf{a}}^{\mathbf{2}}}~\text{ }{{\mathbf{b}}^{\mathbf{2}}}):\text{ }({{\mathbf{a}}^{\mathbf{2}}}~+\text{ }{{\mathbf{b}}^{\mathbf{2}}})\text{ }\mathbf{and}\text{ }({{\mathbf{a}}^{\mathbf{4}}}~\text{ }{{\mathbf{b}}^{\mathbf{4}}}):\text{ }{{\left( \mathbf{a}\text{ }+\text{ }\mathbf{b} \right)}^{\mathbf{4}}}\]

\[\begin{array}{*{35}{l}} {{\left( a\text{ }+\text{ }b \right)}^{2}}:\text{ }{{\left( a\text{ }\text{ }b \right)}^{2}}  \\ ({{a}^{2}}~\text{ }{{b}^{2}}):\text{ }({{a}^{2}}~+\text{ }{{b}^{2}})  \\...

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Using properties of properties, find x from the following equations: (iii) \[\frac{\sqrt{1+x}+\sqrt{1-x}}{\sqrt{1+x}-\sqrt{1-x}}=\frac{a}{b}\] (iv) \[\frac{\sqrt{12x+1}+\sqrt{2x-3}}{\sqrt{12x+1}-\sqrt{2x-3}}=\frac{3}{2}\]

By cross multiplication \[\begin{array}{*{35}{l}} 50x\text{ }\text{ }75\text{ }=\text{ }12x\text{ }+\text{ }1  \\ 50x\text{ }\text{ }12x\text{ }=\text{ }1\text{ }+\text{ }75  \\ \end{array}\] So we...

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If \[(\mathbf{11}{{\mathbf{a}}^{\mathbf{2}}}~+\text{ }\mathbf{13}{{\mathbf{b}}^{\mathbf{2}}})\text{ }(\mathbf{11}{{\mathbf{c}}^{\mathbf{2}}}~\text{ }\mathbf{13}{{\mathbf{d}}^{\mathbf{2}}})\text{ }=\text{ }(\mathbf{11}{{\mathbf{a}}^{\mathbf{2}}}~\text{ }\mathbf{13}{{\mathbf{b}}^{\mathbf{2}}})\text{ }(\mathbf{11}{{\mathbf{c}}^{\mathbf{2}}}~+\text{ }\mathbf{13}{{\mathbf{d}}^{\mathbf{2}}})\], prove that a: b :: c: d.

It is given that \[(\mathbf{11}{{\mathbf{a}}^{\mathbf{2}}}~+\text{ }\mathbf{13}{{\mathbf{b}}^{\mathbf{2}}})\text{ }(\mathbf{11}{{\mathbf{c}}^{\mathbf{2}}}~\text{...

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If \[~\left( \mathbf{4a}\text{ }+\text{ }\mathbf{5b} \right)\text{ }\left( \mathbf{4c}\text{ }\text{ }\mathbf{5d} \right)\text{ }=\text{ }\left( \mathbf{4a}\text{ }\text{ }\mathbf{5d} \right)\text{ }\left( \mathbf{4c}\text{ }+\text{ }\mathbf{5d} \right)\], prove that a, b, c, d are in proportion.

It is given that \[~\left( \mathbf{4a}\text{ }+\text{ }\mathbf{5b} \right)\text{ }\left( \mathbf{4c}\text{ }\text{ }\mathbf{5d} \right)\text{ }=\text{ }\left( \mathbf{4a}\text{ }\text{ }\mathbf{5d}...

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If a: b :: c: d, prove that (iii) \[\left( \mathbf{2a}\text{ }+\text{ }\mathbf{3b} \right)\text{ }\left( \mathbf{2c}\text{ }\text{ }\mathbf{3d} \right)\text{ }=\text{ }\left( \mathbf{2a}\text{ }\text{ }\mathbf{3b} \right)\text{ }\left( \mathbf{2c}\text{ }+\text{ }\mathbf{3d} \right)\] (iv) (la + mb): (lc + mb) :: (la – mb): (lc – mb)

(iii) We know that If a: b :: c: d we get a/b = c/d By multiplying \[2/3\] \[2a/3b\text{ }=\text{ }2c/3d\] By applying componendo and dividendo \[\left( 2a\text{ }+\text{ }3b \right)/\text{ }\left(...

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If a, b, c, d are in continued proportion, prove that: (V) \[{{\left( \frac{a-b}{c}+\frac{a-c}{b} \right)}^{2}}-{{\left( \frac{d-b}{c}+\frac{d-c}{b} \right)}^{2}}={{(a-d)}^{2}}\left( \frac{1}{{{c}^{2}}}-\frac{1}{{{b}^{2}}} \right)\]

It is given that a, b, c, d are in continued proportion Here we get a/b = b/c = c/d = k \[c\text{ }=\text{ }dk,\text{ }b\text{ }=\text{ }ck\text{ }=\text{ }dk\text{ }.\text{ }k\text{ }=\text{...

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If a, b, c, d are in continued proportion, prove that: (iii) \[\left( \mathbf{a}\text{ }+\text{ }\mathbf{d} \right)\text{ }\left( \mathbf{b}\text{ }+\text{ }\mathbf{c} \right)\text{ }\text{ }\left( \mathbf{a}\text{ }+\text{ }\mathbf{c} \right)\text{ }\left( \mathbf{b}\text{ }+\text{ }\mathbf{d} \right)\text{ }=\text{ }{{\left( \mathbf{b}\text{ }\text{ }\mathbf{c} \right)}^{\mathbf{2}}}\] (iv) a: d = triplicate ratio of (a – b): (b – c)

It is given that a, b, c, d are in continued proportion Here we get a/b = b/c = c/d = k \[c\text{ }=\text{ }dk,\text{ }b\text{ }=\text{ }ck\text{ }=\text{ }dk\text{ }.\text{ }k\text{ }=\text{...

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If a, b, c, d are in continued proportion, prove that: (i) \[\frac{{{a}^{3}}+{{b}^{3}}+{{c}^{3}}}{{{b}^{3}}+{{c}^{3}}+{{d}^{3}}}=\frac{a}{d}\] (ii) \[({{\mathbf{a}}^{\mathbf{2}}}~\text{ }{{\mathbf{b}}^{\mathbf{2}}})\text{ }({{\mathbf{c}}^{\mathbf{2}}}~\text{ }{{\mathbf{d}}^{\mathbf{2}}})\text{ }=\text{ }{{({{\mathbf{b}}^{\mathbf{2}}}~\text{ }{{\mathbf{c}}^{\mathbf{2}}})}^{\mathbf{2}}}\]

It is given that a, b, c, d are in continued proportion Here we get a/b = b/c = c/d = k \[c\text{ }=\text{ }dk,\text{ }b\text{ }=\text{ }ck\text{ }=\text{ }dk\text{ }.\text{ }k\text{ }=\text{...

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If a, b, c are in continued proportion, prove that: (v) \[\mathbf{abc}\text{ }{{\left( \mathbf{a}\text{ }+\text{ }\mathbf{b}\text{ }+\text{ }\mathbf{c} \right)}^{\mathbf{3}}}~=\text{ }{{\left( \mathbf{ab}\text{ }+\text{ }\mathbf{bc}\text{ }+\text{ }\mathbf{ca} \right)}^{\mathbf{3}}}\] (vi) \[\left( \mathbf{a}\text{ }+\text{ }\mathbf{b}\text{ }+\text{ }\mathbf{c} \right)\text{ }\left( \mathbf{a}\text{ }\text{ }\mathbf{b}\text{ }+\text{ }\mathbf{c} \right)\text{ }=\text{ }{{\mathbf{a}}^{\mathbf{2}}}~+\text{ }{{\mathbf{b}}^{\mathbf{2}}}~+\text{ }{{\mathbf{c}}^{\mathbf{2}}}\]

It is given that a, b, c are in continued proportion So we get a/b = b/c = k (v) LHS = \[abc\text{ }{{\left( a\text{ }+\text{ }b\text{ }+\text{ }c \right)}^{3}}\] We can write it as \[=\text{...

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If a, b, c are in continued proportion, prove that: (iii) \[\mathbf{a}:\text{ }\mathbf{c}\text{ }=\text{ }({{\mathbf{a}}^{\mathbf{2}}}~+\text{ }{{\mathbf{b}}^{\mathbf{2}}}):\text{ }({{\mathbf{b}}^{\mathbf{2}}}~+\text{ }{{\mathbf{c}}^{\mathbf{2}}})\] (iv) \[~{{\mathbf{a}}^{\mathbf{2}}}{{\mathbf{b}}^{\mathbf{2}}}{{\mathbf{c}}^{\mathbf{2}}}~({{\mathbf{a}}^{-\mathbf{4}}}~+\text{ }{{\mathbf{b}}^{-\mathbf{4}}}~+\text{ }{{\mathbf{c}}^{-\mathbf{4}}})\text{ }=\text{ }{{\mathbf{b}}^{-\mathbf{2}}}~({{\mathbf{a}}^{\mathbf{4}}}~+\text{ }{{\mathbf{b}}^{\mathbf{4}}}~+\text{ }{{\mathbf{c}}^{\mathbf{4}}})\]

It is given that a, b, c are in continued proportion So we get a/b = b/c = k   (iii) \[~a:\text{ }c\text{ }=\text{ }({{a}^{2}}~+\text{ }{{b}^{2}}):\text{ }({{b}^{2}}~+\text{ }{{c}^{2}})\] We...

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If x, y, z are in continued proportion, prove that:\[{{\left( \mathbf{x}\text{ }+\text{ }\mathbf{y} \right)}^{\mathbf{2}}}/\text{ }{{\left( \mathbf{y}\text{ }+\text{ }\mathbf{z} \right)}^{\mathbf{2}}}~=\text{ }\mathbf{x}/\mathbf{z}\]

It is given that x, y, z are in continued proportion Consider x/y = y/z = k So we get y = kz \[x\text{ }=\text{ }yk\text{ }=\text{ }kz\text{ }\times \text{ }k\text{ }=\text{ }{{k}^{2}}z\] Therefore,...

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If a, b, c and d are in proportion, prove that: (vii) \[\frac{{{a}^{2}}+{{b}^{2}}}{{{c}^{2}}+{{d}^{2}}}=\frac{ab+ad-bc}{bc+cd-ad}\] (viii) \[abcd\left[ \frac{1}{{{a}^{2}}}+\frac{1}{{{b}^{2}}}+\frac{1}{{{c}^{2}}}+\frac{1}{{{d}^{2}}} \right]={{a}^{2}}+{{b}^{2}}+{{c}^{2}}+{{d}^{2}}\]

It is given that a, b, c, d are in proportion Consider a/b = c/d = k a = b, c = dk Therefore, LHS = RHS. So we get = d2 (1 + k2) + b2 (1 + k2) = (1 + k2) (b2 + d2) RHS = a2 + b2 + c2 + d2 We can...

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If a, b, c and d are in proportion, prove that: (i) \[\left( \mathbf{5a}\text{ }+\text{ }\mathbf{7v} \right)\text{ }\left( \mathbf{2c}\text{ }\text{ }\mathbf{3d} \right)\text{ }=\text{ }\left( \mathbf{5c}\text{ }+\text{ }\mathbf{7d} \right)\text{ }\left( \mathbf{2a}\text{ }\text{ }\mathbf{3b} \right)\] (ii) (ma + nb): b = (mc + nd): d

It is given that a, b, c, d are in proportion Consider a/b = c/d = k a = b, c = dk (i) LHS = \[\left( 5a\text{ }+\text{ }7b \right)\text{ }\left( 2c\text{ }\text{ }3d \right)\] Substituting the...

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If a/b = c/d = e/f prove that: \[\frac{{{a}^{2}}}{{{b}^{2}}}+\frac{{{c}^{2}}}{{{d}^{2}}}+\frac{{{e}^{2}}}{{{f}^{2}}}=\frac{ac}{bd}+\frac{ce}{df}+\frac{ae}{df}\] (iv) \[bdf{{\left[ \frac{a+b}{b}+\frac{c+d}{d}+\frac{c+f}{f} \right]}^{3}}=27(a+b)(c+d)(e+f)\]

Consider a/b = c/d = e/f = k So we get a = bk, c = dk, e = fk Therefore, LHS = RHS. So we get \[=\text{ }bdf\text{ }{{\left( k\text{ }+\text{ }1\text{ }+\text{ }k\text{ }+\text{ }1\text{ }+\text{...

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If a/b = c/d = e/f prove that: (i) \[({{\mathbf{b}}^{\mathbf{2}}}~+\text{ }{{\mathbf{d}}^{\mathbf{2}}}~+\text{ }{{\mathbf{f}}^{\mathbf{2}}})\text{ }({{\mathbf{a}}^{\mathbf{2}}}~+\text{ }{{\mathbf{c}}^{\mathbf{2}}}~+\text{ }{{\mathbf{e}}^{\mathbf{2}}})\text{ }=\text{ }{{\left( \mathbf{ab}\text{ }+\text{ }\mathbf{cd}\text{ }+\text{ }\mathbf{ef} \right)}^{\mathbf{2}}}\] (ii) \[\frac{{{({{a}^{3}}+{{c}^{3}})}^{2}}}{{{({{b}^{3}}+{{d}^{3}})}^{2}}}=\frac{{{e}^{6}}}{{{f}^{6}}}\]

Consider a/b = c/d = e/f = k So we get a = bk, c = dk, e = fk (i) LHS = \[({{b}^{2}}~+\text{ }{{d}^{2}}~+\text{ }{{f}^{2}})\text{ }({{a}^{2}}~+\text{ }{{c}^{2}}~+\text{ }{{e}^{2}})\] We can write it...

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16. If x/a = y/b = z/c, prove that (i) \[\frac{{{x}^{3}}}{{{a}^{2}}}+\frac{{{y}^{3}}}{{{b}^{2}}}+\frac{{{z}^{3}}}{{{c}^{2}}}=\frac{{{(x+y+z)}^{3}}}{{{(a+b+c)}^{2}}}\] (ii)\[{{\left[ \frac{{{a}^{2}}{{x}^{2}}+{{b}^{2}}{{y}^{2}}+{{c}^{2}}{{z}^{2}}}{{{a}^{3}}x+{{b}^{3}}y+{{c}^{3}}z} \right]}^{3}}=\frac{xyz}{abc}\]

It is given that x/a = y/b = z/c We can write it as x = ak, y = bk and z = ck Therefore, LHS = RHS. Therefore, LHS = RHS.

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If y is mean proportional between x and z, prove that \[\mathbf{xyz}\text{ }{{\left( \mathbf{x}\text{ }+\text{ }\mathbf{y}\text{ }+\text{ }\mathbf{z} \right)}^{\mathbf{3}}}~=\text{ }{{\left( \mathbf{xy}\text{ }+\text{ }\mathbf{yz}\text{ }+\text{ }\mathbf{zx} \right)}^{\mathbf{3}}}\]

It is given that y is mean proportional between x and z We can write it as \[{{y}^{2}}~=\text{ }xz\]…… (1) Consider LHS = \[xyz\text{ }{{\left( x\text{ }+\text{ }y\text{ }+\text{ }z \right)}^{3}}\]...

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If b is the mean proportional between a and c, prove that (ab + bc) is the mean proportional between \[({{\mathbf{a}}^{\mathbf{2}}}~+\text{ }{{\mathbf{b}}^{\mathbf{2}}})\text{ }\mathbf{and}\text{ }({{\mathbf{b}}^{\mathbf{2}}}~+\text{ }{{\mathbf{c}}^{\mathbf{2}}})\]

It is given that b is the mean proportional between a and c \[{{b}^{2}}~=\text{ }ac\]…. (1) Here (ab + bc) is the mean proportional between \[({{\mathbf{a}}^{\mathbf{2}}}~+\text{...

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If \[\mathbf{k}\text{ }+\text{ }\mathbf{3},\text{ }\mathbf{k}\text{ }+\text{ }\mathbf{2},\text{ }\mathbf{3k}\text{ }\text{ }\mathbf{7}\text{ }\mathbf{and}\text{ }\mathbf{2k}\text{ }\text{ }\mathbf{3}\] are in proportion, find k.

It is given that \[\mathbf{k}\text{ }+\text{ }\mathbf{3},\text{ }\mathbf{k}\text{ }+\text{ }\mathbf{2},\text{ }\mathbf{3k}\text{ }\text{ }\mathbf{7}\text{ }\mathbf{and}\text{ }\mathbf{2k}\text{...

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Find the fourth proportional to (iii) \[\mathbf{1}.\mathbf{5},\text{ }\mathbf{2}.\mathbf{5},\text{ }\mathbf{4}.\mathbf{5}\] (iv) \[\mathbf{9}.\mathbf{6}\text{ }\mathbf{kg},\text{ }\mathbf{7}.\mathbf{2}\text{ }\mathbf{kg},\text{ }\mathbf{28}.\mathbf{8}\text{ }\mathbf{kg}\]

(iii) \[1.5,\text{ }2.5,\text{ }4.5\] Consider x as the fourth proportional to \[1.5,\text{ }2.5,\text{ }4.5\] \[1.5:\text{ }2.5\text{ }::\text{ }4.5:\text{ }x\] We can write it as \[1.5\text{...

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Find the value of x in the following proportions: (iii) \[\mathbf{2}.\mathbf{5}:\text{ }\mathbf{1}.\mathbf{5}\text{ }=\text{ }\mathbf{x}:\text{ }\mathbf{3}\] (iv) \[\mathbf{x}:\text{ }\mathbf{50}\text{ }::\text{ }\mathbf{3}:\text{ }\mathbf{2}\]

(iii)\[~2.5:\text{ }1.5\text{ }=\text{ }x:\text{ }3\] We can write it as \[1.5\text{ }\times \text{ }x\text{ }=\text{ }2.5\text{ }\times \text{ }3\] So we get \[\begin{array}{*{35}{l}} x\text{...

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(i) The monthly pocket money of Ravi and Sanjeev are in the ratio \[5:7\]. Their expenditures are in the ratio \[3:5\]. If each saves Rs \[80\] per month, find their monthly pocket money. (ii) In class X of a school, the ratio of the number of boys to that of the girls is \[4:3\]. If there were \[20\] more boys and \[12\] less girls, then the ratio would have been \[2:1\]. How many students were there in the class?

(i) Consider the monthly pocket money of Ravi and Sanjeev as \[5x\] and \[7x\] Their expenditure is \[3y\] and \[5y\] respectively. \[5x\text{ }\text{ }3y\text{ }=\text{ }80\] …… (1) \[7x\text{...

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(i) In a mixture of \[45\] litres, the ratio of milk to water is \[13:2\]. How much water must be added to this mixture to make the ratio of milk to water as \[3:1\]? (ii) The ratio of the number of boys to the numbers of girls in a school of \[560\] pupils is \[5:3\]. If \[10\] new boys are admitted, find how many new girls may be admitted so that the ratio of the number of boys to the number of girls may change to \[3:2\].

(i) It is given that Mixture of milk to water = \[45\] litres Ratio of milk to water = \[13:2\] Sum of ratio = \[13\text{ }+\text{ }2\text{ }=\text{ }15\] Here the quantity of milk = \[\left(...

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(i) A certain sum was divided among A, B and C in the ratio \[7:5:4\]. If B got Rs \[500\] more than C, find the total sum divided. (ii) In a business, A invests Rs \[50000\] for \[6\] months, B Rs \[60000\] for \[4\] months and C Rs \[80000\] for \[5\] months. If they together earn Rs \[18800\] find the share of each.

(i) It is given that Ratio between A, B and C = \[7:\text{ }5:\text{ }4\] Consider A share = \[7x\] B share = \[5x\] C share = \[4x\] So the total sum =\[~7x\text{ }+\text{ }5x\text{ }+\text{...

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(i) A woman reduces her weight in the ratio \[7:5\]. What does her weight become if originally it was \[91\] kg. (ii) A school collected Rs 2100 for charity. It was decided to divide the money between an orphanage and a blind school in the ratio of 3: 4. How much money did each receive?

(i) Ratio of original and reduced weight of woman = \[7:5\] Consider original weight = \[7x\] Reduced weight = \[5x\] Here original weight = \[91\]  kg So the reduced weight = \[~\left( 91\text{...

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(i) Find two numbers in the ratio of \[\mathbf{8}:\text{ }\mathbf{7}\] such that when each is decreased by \[\mathbf{12}\text{ }{\scriptscriptstyle 1\!/\!{ }_2}\], they are in the ratio \[\mathbf{11}:\text{ }\mathbf{9}\]. (ii) The income of a man is increased in the ratio of \[\mathbf{10}:\text{ }\mathbf{11}\]. If the increase in his income is Rs \[\mathbf{600}\] per month, find his new income.

(i) Ratio = \[\mathbf{8}:\text{ }\mathbf{7}\] Consider the numbers as \[8x\] and \[7x\] Using the condition \[\left[ 8x\text{ }\text{ }25/2 \right]/\text{ }\left[ 7x\text{ }\text{ }25/2...

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(i) If \[\left( \mathbf{x}\text{ }\text{ }\mathbf{9} \right):\text{ }\left( \mathbf{3x}\text{ }+\text{ }\mathbf{6} \right)\] is the duplicate ratio of \[\mathbf{4}:\text{ }\mathbf{9}\], find the value of x. (ii) If \[\left( \mathbf{3x}\text{ }+\text{ }\mathbf{1} \right):\text{ }\left( \mathbf{5x}\text{ }+\text{ }\mathbf{3} \right)\] is the triplicate ratio of \[\mathbf{3}:\text{ }\mathbf{4}\], find the value of x.

(i) \[\left( x\text{ }\text{ }9 \right)/\text{ }\left( 3x\text{ }+\text{ }6 \right)\text{ }=\text{ }{{\left( 4/9 \right)}^{2}}\] So we get \[\left( x\text{ }\text{ }9 \right)/\text{ }\left( 3x\text{...

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(i) If \[(\mathbf{4}{{\mathbf{x}}^{\mathbf{2}}}~+\text{ }\mathbf{xy}):\text{ }(\mathbf{3xy}\text{ }\text{ }{{\mathbf{y}}^{\mathbf{2}}})\text{ }=\text{ }\mathbf{12}:\text{ }\mathbf{5}\], find \[\left( \mathbf{x}\text{ }+\text{ }\mathbf{2y} \right):\text{ }\left( \mathbf{2x}\text{ }+\text{ }\mathbf{y} \right)\] (ii) If \[\mathbf{y}\text{ }\left( \mathbf{3x}\text{ }\text{ }\mathbf{y} \right):\text{ }\mathbf{x}\text{ }\left( \mathbf{4x}\text{ }+\text{ }\mathbf{y} \right)\text{ }=\text{ }\mathbf{5}:\text{ }\mathbf{12}\]. Find \[({{\mathbf{x}}^{\mathbf{2}}}~+\text{ }{{\mathbf{y}}^{\mathbf{2}}}):\text{ }{{\left( \mathbf{x}\text{ }+\text{ }\mathbf{y} \right)}^{\mathbf{2}}}\]

(i) \[(\mathbf{4}{{\mathbf{x}}^{\mathbf{2}}}~+\text{ }\mathbf{xy}):\text{ }(\mathbf{3xy}\text{ }\text{ }{{\mathbf{y}}^{\mathbf{2}}})\text{ }=\text{ }\mathbf{12}:\text{ }\mathbf{5}\] We can write it...

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(i) If \[\mathbf{3x}\text{ }+\text{ }\mathbf{5y}/\text{ }\mathbf{3x}\text{ }\text{ }\mathbf{5y}\text{ }=\text{ }\mathbf{7}/\mathbf{3}\],find x: y. (ii) If \[\mathbf{a}:\text{ }\mathbf{b}\text{ }=\text{ }\mathbf{3}:\text{ }\mathbf{11}\], find \[\left( \mathbf{15a}\text{ }\text{ }\mathbf{3b} \right):\text{ }\left( \mathbf{9a}\text{ }+\text{ }\mathbf{5b} \right)\].

(i) \[\mathbf{3x}\text{ }+\text{ }\mathbf{5y}/\text{ }\mathbf{3x}\text{ }\text{ }\mathbf{5y}\text{ }=\text{ }\mathbf{7}/\mathbf{3}\] By cross multiplication \[9x\text{ }+\text{ }15y\text{ }=\text{...

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(i) If \[\mathbf{A}:\text{ }\mathbf{B}\text{ }=\text{ }\mathbf{1}/\mathbf{4}:\text{ }\mathbf{1}/\mathbf{5}\text{ }\mathbf{and}\text{ }\mathbf{B}:\text{ }\mathbf{C}\text{ }=\text{ }\mathbf{1}/\mathbf{7}:\text{ }\mathbf{1}/\mathbf{6}\], find A: B: C. (ii) If \[\mathbf{3A}\text{ }=\text{ }\mathbf{4B}\text{ }=\text{ }\mathbf{6C}\], find A: B: C

(i) We know that \[\begin{array}{*{35}{l}} A:\text{ }B\text{ }=\text{ }1/4\text{ }\times \text{ }5/1\text{ }=\text{ }5/4  \\ B:\text{ }C\text{ }=\text{ }1/7\text{ }\times \text{ }6/1\text{ }=\text{...

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(i) If \[\mathbf{A}:\text{ }\mathbf{B}\text{ }=\text{ }\mathbf{2}:\text{ }\mathbf{3},\text{ }\mathbf{B}:\text{ }\mathbf{C}\text{ }=\text{ }\mathbf{4}:\text{ }\mathbf{5}\text{ }\mathbf{and}\text{ }\mathbf{C}:\text{ }\mathbf{D}\text{ }=\text{ }\mathbf{6}:\text{ }\mathbf{7}\], find A: D. (ii) If \[\mathbf{x}:\text{ }\mathbf{y}\text{ }=\text{ }\mathbf{2}:\text{ }\mathbf{3}\text{ }\mathbf{and}\text{ }\mathbf{y}:\text{ }\mathbf{z}\text{ }=\text{ }\mathbf{4}:\text{ }\mathbf{7}\], find x: y: z.

(i) It is given that \[\mathbf{A}:\text{ }\mathbf{B}\text{ }=\text{ }\mathbf{2}:\text{ }\mathbf{3},\text{ }\mathbf{B}:\text{ }\mathbf{C}\text{ }=\text{ }\mathbf{4}:\text{ }\mathbf{5}\text{...

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Arrange the following ratios in ascending order of magnitude: \[\mathbf{2}:\text{ }\mathbf{3},\text{ }\mathbf{17}:\text{ }\mathbf{21},\text{ }\mathbf{11}:\text{ }\mathbf{14}\text{ }\mathbf{and}\text{ }\mathbf{5}:\text{ }\mathbf{7}\]

It is given that \[\mathbf{2}:\text{ }\mathbf{3},\text{ }\mathbf{17}:\text{ }\mathbf{21},\text{ }\mathbf{11}:\text{ }\mathbf{14}\text{ }\mathbf{and}\text{ }\mathbf{5}:\text{ }\mathbf{7}\] We can...

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Find the compounded ratio of: (iii) \[\left( \mathbf{a}\text{ }\text{ }\mathbf{b} \right):\text{ }\left( \mathbf{a}\text{ }+\text{ }\mathbf{b} \right),\text{ }{{\left( \mathbf{a}\text{ }+\text{ }\mathbf{b} \right)}^{\mathbf{2}}}:\text{ }({{\mathbf{a}}^{\mathbf{2}}}~+\text{ }{{\mathbf{b}}^{\mathbf{2}}})\text{ }\mathbf{and}\text{ }({{\mathbf{a}}^{\mathbf{4}}}~\text{ }{{\mathbf{b}}^{\mathbf{4}}}):\text{ }{{({{\mathbf{a}}^{\mathbf{2}}}~\text{ }{{\mathbf{b}}^{\mathbf{2}}})}^{\mathbf{2}}}\]

(iii) \[\left( \mathbf{a}\text{ }\text{ }\mathbf{b} \right):\text{ }\left( \mathbf{a}\text{ }+\text{ }\mathbf{b} \right),\text{ }{{\left( \mathbf{a}\text{ }+\text{ }\mathbf{b}...

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Find the compounded ratio of: (i) \[\mathbf{2}:\text{ }\mathbf{3}\text{ }\mathbf{and}\text{ }\mathbf{4}:\text{ }\mathbf{9}\] (ii) \[\mathbf{4}:\text{ }\mathbf{5},\text{ }\mathbf{5}:\text{ }\mathbf{7}\text{ }\mathbf{and}\text{ }\mathbf{9}:\text{ }\mathbf{11}\]

(i) \[\mathbf{2}:\text{ }\mathbf{3}\text{ }\mathbf{and}\text{ }\mathbf{4}:\text{ }\mathbf{9}\] We know that Compound ratio \[\begin{array}{*{35}{l}} ~=\text{ }2/3\text{ }\times \text{ }4/9  \\...

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