Question

The coefficient of x^p and x^q (p and q are positive integers) in the expansion of (1 + x)^{p + q} are

(A) equal 

(B) equal with opposite signs

(C) reciprocal of each other 

(D) none of these

Answer 1

A is the correct choice. Coefficient of x^p and x^q in the expansion of (1 + x)^{p+ q} are ^{p + q}C_p and p + ^qC_q

and 

Hence (a) is the correct answer.