Question

The probability of getting 2 heads, when two coins are tossed, is [CBSE 2012]

(a) 1
(b) $\frac{3}{4}$
(c) $\frac{1}{2}$
(d) $\frac{1}{4}$

Answer 1

All possible outcomes are HH, HT, TH and TT.

​Total number of outcomes = 4.

Getting 2 heads means getting HH.

Numbers of favourable outcomes = 1.

∴ P(getting 2 heads) = $\frac{\mathrm{Number}\mathrm{of}\mathrm{favourable}\mathrm{outcomes}}{\mathrm{Number}\mathrm{of}\mathrm{all}\mathrm{possible}\mathrm{outcomes}}$
= $\frac{1}{4}$

Thus, the probability of getting 2 heads is $\frac{1}{4}$.

Hence, the correct answer is option (d).