Answer
$0.5$
Work Step by Step
We know that probability of the event F is $P(F)=\frac{\text{number of favourable outcomes}}{\text{number of all outcomes}}=\frac{n(F)}{n(S)}$.
We have $E=\{1,3,5,7,9\}$ so $n(F)=5$ and $n(S)=10$.
Thus,
$P(F)=\dfrac{5}{10}=0.5$.
