If nPr=5040(n−1Cr−1+n−1Cr),then r =
If 2:9 :: x:27 then find the value of x.
If 4x+85x+8=56, then x = ?
(a) 4
(b) 6
(c) 8
(d) 12
If the coefficients of Tr,Tr+1,Tr+2 terms of (1+x)14 are in A.P., then r =
If 1+∑18r=0(r(r+2)+1)r!=n!, then n is not divisible by