Question:
The probability of getting 2 heads, when two coins are tossed, is
(a) 1
(b) $\frac{3}{4}$
(c) $\frac{1}{2}$
(d) $\frac{1}{4}$
Solution:
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
$\therefore \mathrm{P}($ getting 2 heads $)=\frac{\text { Number of favourable outcomes }}{\text { Number of all possible outcomes }}$
$=\frac{1}{4}$
Thus, the probability of getting 2 heads is $\frac{1}{4}$.
Hence, the correct answer is option (d).