Question

Three unbiased coins are tossed What is the probability of getting at least $2$ heads?

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

Answer 1

Answer: (B)

$\frac{1}{2}$

Here S = {TTT, TTH, THT, HTT, THH, HTH, HHT, HHH}
Let E= event of getting at least two heads
= {THH, HTH, HHT, HHH}
$\therefore P\left(E\right)=\frac{n\left(E\right)}{n\left(S\right)}=\frac{4}{8}=\frac{1}{2}$