Answer
$\frac{3}{26}$
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 $_{26}C_3=2600$, out of these $_6C_2\cdot_{20}C_1=300$ correspond to the desirable selection.
Hence here the probability is $\frac{300}{2600}=\frac{3}{26}$