toss a coin with a probability of heads 0.3 Five times. Let X be the number of tails. Find P(X=2) and P(X greater than or equal to 1) Solution Given Probability of head = 0.3 Five times So P(X=2) = 5c2 0.33 0.72 = 0.132 P(X greater than or equal to 1) = 1-P(X<1) = 1-0.35 = 0.998.