Question

Two unbiased dice are rolled once. Find the probability of getting sum less than $5$.

• A. $\frac{1}{6}$
• B. $\frac{3}{4}$
• C. $\frac{2}{3}$
• D. $\frac{1}{5}$

Answer 1

Answer: (A)

$\frac{1}{6}$

When two dice are thrown, the sample space is given (refer the below diagram)
$n\left(S\right)=6\times 6=36$
Let $C$ be the event of getting a sum less than $5$.
$C=(1,1),(1,2),(1,3),(2,1),(2,2),(3,1)$
$n\left(C\right)=6$
$P\left(C\right)=$ $\frac{n\left(C\right)}{n\left(S\right)}=\frac{6}{36}=\frac{1}{6}$