(i) Here, total number of trials = 100 times
Number of heads got (H, H) = 21
∴ P(E) = Number of trials in which two heads occurs/Total number of trials = 21/100
(ii) Total number of trials = 100 times
Number of exactly one head = 55
∴ P(E) = 55/100 = 11/20
(iii) Total number of trials = 100 times
Number of head = 24
∴ Probability = 24/100 = 16/25