Answer
See below.
Work Step by Step
We know that probability$=\frac{\text{number of favourable outcomes}}{\text{number of all outcomes}}.$
Let $X$ be the even numbers in $S$, thus $X=\{2,4,6,8,10\}$.
Hence here probability$=\frac{|X|}{|S|}=\frac{5}{10}=0.5.$
