Question

If a coin is tossed three times, then what is the probability that at least one head occurs in the three trials?

• A. $\frac{7}{8}$
• B. $\frac{5}{6}$
• C. $\frac{1}{2}$
• D. $\frac{4}{6}$

Answer 1

The correct option is A

$\frac{7}{8}$

Possible outcomes = {HHH, HHT, HTH, HTT, THH, THT, TTH, TTT}
Probability of getting no head = $\frac{1}{8}$
Probability of getting at least one head $=1-\frac{1}{8}$

$=\frac{7}{8}$