A. r. 2r
B. (2r-1)2r
C. r. 22r+1
D. (2r+1) 2r
If nεN, n is odd then n(n2-1) is divisible by
If the middle term of (1+x)2n is 1.3.5...(2n-1)k/n! then k=
The general term of (2a-3b)-1/2 is
The coefficient of xr in (1+x)2/(1-2x)3 is
49n+16n+k is divisible by 64 for n?N. Then the numerically least –ve integer value of k is
The coefficient of xr (0<r<n-1) in the expansion of (x+3)n-1+(x+3)n-2. (x+2)+ (x+3)n-3. (x+2)2+……+(x+2)n-1 is
nC0+nC1+nC2+………+nCn =
If the 5th term is 24 times the 3rd term in the expansion of (1+x)11 then x=
If Tr+1 is the term independent of x in (3x-5/x3)8 then r=
The 4th term of (1-2x)-1 when x=1/3 is