Answer
$\frac{10}{1001}$
Work Step by Step
We know that $probability=\frac{\text{number of favorable outcomes}}{\text{number of all outcomes}}$
The number of all outcomes is $_{15}C_6=\frac{15!}{6!9!}=5005$, out of these $50$ correspond to the desirable selection.
Hence here the probability is $\frac{50}{5005}=\frac{10}{1001}$
