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

Given data

• Number of coins = 3; each fair (unbiased).

Concept/Approach
At most two heads = 1 − P(three heads).

Step-by-Step calculation
Total outcomes = 2³ = 8 P(3 heads) = 1 ÷ 8 P(at most 2 heads) = 1 − 1÷8 = 7÷8

Verification/Alternative
Direct sum: P(0H) + P(1H) + P(2H) = 1÷8 + 3÷8 + 3÷8 = 7÷8.

Final Answer
7/8