Question

On the occasion of Dipawali festival each student of a class sends greeting cards to others. If there are 20 students in the class, the number of cards send by students is

(A) 20C2

(B) 20P2

(C) 2 × 20C2

(D) 2 × 20P2

Answer 1

The correct option (B) 20P2

(C) 2 × 20C2

Explanation:

Number of ways = 20C2 × 2!

= 20P2