Binomial Coefficients
Trending Questions
If nCr−1 = 36, nCr = 84 and nCr+1 = 126, then the value of r is
2
3
4
1
The coefficient of x5 in the expansion of
(1+x2)5 (1+x)4 is
40
None of these
30
60
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.
If a1, a2, a3, a4 are the coefficients of any four consecutive terms in the expansion of (1+x)n, then a1a1+a2+a3a3+a4=
12 a2a2+a3
a2a2+a3
2a2a2+a3
2a3a2+a3
Find four numbers forming a geometric progression in which the third term is greater than the first term by 9 and the second term is greater than by 4th by a18.
For 1≤r≤n , the value of \( {}^nC_r + {}^{n-1}C_r+ {}^{n-2}C_r.....+...+....+ {}^rC_r \space is : \)
nCr+1
n+1Cr
None
n+1Cr+1
Prove that the coefficient of xn in the binomial expansion of (1+x)2n is twice the coefficient of xn in the binomial expansion of (1+x)2n−1.
Find the coefficient of x in the expansion of (1−3x+7x2)(1−x)16
If the three consecutive coefficient in the
expansion of (1+x)n are 28, 56 and 70, then the
value of n is
6
10
4
8
Coefficient of x25 in (1+x+x2+x3+...+x10)7 is:
31
31C14 - 7. 20C14
31C16 - 7. 20C14