Answer : Given, nCr–1 = 36,
nCr = 84 and nCr+1 = 126
To find:r=?
⇒2(n-r)=3(r+1)
⇒2n-5r=3….(2)
From equations 1 & 2 we get n=9 & r=3
Ans: r = 3
Answer : Given, nCr–1 = 36,
nCr = 84 and nCr+1 = 126
To find:r=?
⇒2(n-r)=3(r+1)
⇒2n-5r=3….(2)
From equations 1 & 2 we get n=9 & r=3
Ans: r = 3