Three unbiased coins are tossed. What is the probability of getting at most two heads? Choose the correct choice.
A) 9/7  B) 7/8  C) 1/2  D) 5/4  E) 3/8
Explanation:   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   Answer:7/8
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Three unbiased coins are tossed. What is the probability of getting at most two heads?