A box has 6 black, 4 red, 2 white and 3 blue shirts. Find the probability of drawing 2 black shirts if they are picked randomly?

Answer: Option D

We want 2 black shirts
That means choose one and then choose other from remaining shirts
There are 6 black shirts
Total 15 shirts
So probability for 2 black shirts
$$\begin{array}{rl}& =\frac{6}{15}\times \frac{5}{14}\\ & =\frac{1}{7}\end{array}$$