Three unbiased coins are tossed. What is the probability of getting at most two heads?

Three unbiased coins are tossed. What is the probability of getting at most two heads?

A 3/4

B 7/8

C 1/2

D 1/4

Solution

Correct Answer: Option B

Here S = {TTT, TTH, THT, HTT, THH, HTH, HHT, HHH}

Let E = event of getting at most two heads.

Then E = {TTT, TTH, THT, HTT, THH, HTH, HHT}.

P(E) =n(E)/n(S)=7/8.