Your sock drawer has six white socks, six brown socks, and four black socks. you randomly pick two socks and get a matching pair of black socks. find the probability of this occuring.

Total socks in the drawers = 6 + 6 + 4 = 16 

Probability of picking the first black sock = 4/16
Probability of picking the second black sock = 3/15

Probability of picking two black socks = 4/16 × 3/15 = 1/20