Sock-ability

Probability Level 3

I have 7 pairs of red socks, 6 pairs of blue socks, and 5 pairs of green socks in my drawer. If I randomly pick out 4 socks, what is the probability that I will get (at least) a matching pair?

Details and Assumptions:

Besides the color, there is no difference between a left sock and a right sock.

0

\frac{1}{4}

\frac{1}{3}

\frac{1}{2}

\frac{2}{3}

\frac{3}{4}

1