Answer
$\frac{3}{14}$
Work Step by Step
We know that $probability=\frac{\text{number of favourable outcomes}}{\text{number of all outcomes}}$
The number of all outcomes is $31+54+42+20+47+58=252$
There are $54$ people (who work in marketing)
Hence the probability here is: $\frac{54}{252}=\frac{3}{14}$
