Answer
$0.5$
Work Step by Step
We know that probability of the event E is $P(E)=\frac{\text{number of favourable outcomes}}{\text{number of all outcomes}}=\frac{n(E)}{n(S)}$.
We have $E=\{2,4,6,8,10\}$, so $n(E)=5$ and $n(S)=10$.
Thus,
$P(E)=\dfrac{5}{10}=0.5$.
