Question

three coins are tossed find the probability of getting a)3 heading b) exactly 2 heads c) at least two heads

Answer 1

Let ‘E1’ = Event of getting all heads, Then E1 = { HHH }
|E1| = 1
P(E1) = |E1| / |S| = 1 / 8
(ii) Let E2 = Event of getting ‘2’ heads. Then:
E2 = { HHT, HTH, THH }
|E2| = 3
P (E2) = 3 / 8
(iii) Let E3 = Event of getting at least one head. Then:
E3 = { HHH, HHT, HTH, THH, HTT, THT, TTH }
|E3| = 7
P (E3) = 7 / 8
(iv) Let E4 = Event of getting at least one head, Then:
E4 = { HHH, HHT, HTH, THH, }
|E4| = 4
P (E4) = 4/8 = 1/2

I hope it helps you