Question

Three unbiased coins are tossed, what is the probability of getting at least $2$ tails?

• A. $\frac{1}{2}$
• B. $\frac{1}{4}$
• C. $\frac{1}{8}$
• D. $\frac{2}{3}$

Answer 1

The correct option is A $\frac{1}{2}$

Three coins tossed.

Total cases: $2^3=8$

Total cases with at least $2$ tails are: $4\to \{TTT,TTH,THT,HTT\}$

Required probability:

$P=\frac{4}{8}=\frac{1}{2}$