Question

Consider the expression (a + b)n. According to the Binomial Theorem, the kth term in the expanded form of this expression (where k≤ n) is A) C(n, k)*xkyn-k B) C(n, k-1)*xkyn-k C) C(n-1, k)*xkyn-k D) C(n-1, k-1)*xkyn-k

Answer 1

The correct answer is 

C.

Answer 2

The Given expression is

   $(a+b)^n$

There are (n+1) terms in above expression.

To find the k-th term in the expression , we will evaluate (k+1)-th term.

   $T_{k+1}=_{k}^{n}\textrm{C} \times a^{k} \times b^{n-k}$

⇒If the expression is of the form,

   $(x+y)^n$

Then k-th term is given by

  $T_{k+1}=_{k}^{n}\textrm{C} \times x^{k} \times y^{n-k}$

Option A