Question

A die is thrown once. The probability of getting a prime number is
(a) $\frac{2}{3}$ (b) $\frac{1}{3}$ (c) $\frac{1}{2}$ (d) $\frac{1}{6}$

Answer 1

The correct option is (c): $\frac{1}{2}$

When a die is thrown, all possible outcomes are $1,2,3,4,5,6$

Prime number in these outcomes are $2,3,5$

The total no. of possible outcomes $=6$
No. of favourable outcomes (getting prime number) $=3$
Let this event be E (getting a prime number).

$P\left(E\right)=$ $\frac{\text{No.of favourable outcomes}}{\text{Total no. of outcomes}}$

$=\frac{3}{6}$

$=\frac{1}{2}$

So , probability of getting a prime number is $\frac{1}{2}$