Question

Two coins are tossed simultaneously. Find the probability of getting 'no head'.

Answer 1

Probability of getting no head =1/4

Answer 2

Let E4 = event of getting no head. Then, 
E4 = {TT} and, therefore, n(E4) = 1. 
Therefore, P(getting no head) = P(E4) = n(E4)/n(S) = ¼.