In the expansion of (1 + x)n the coefficients of pth and (p + 1) th terms are respectively p and q, then p + q is equal to
n
n + 1
n + 2
n + 3
If the coefficient of (2r + 1)th term and (r + 2)th term in the expansion of (1 + x)43 are equal, then r is equal to :
12
14
16
18
Coefficient of x10 in the expansion of (2 + 3x)e- x is
B.