Mixed in a drawer are 4 blue socks and 8 gray socks You poll

Mixed in a drawer are 4 blue socks, and 8 gray socks. You poll out two socks, one at a time , without locking find the probability a getting 2 socks of the same color. The probability of getting 2 socks of the same color is

Solution

total number of socks = 4 + 8 + 8 = 20

probability of getting 2 socks of same color

= probability of getting 2 blues + probability of getting 2 whites + probability of getting 2 grays

= 4/20 * 3/19 + 8/20 * 7/19 + 8/20 * 7/19

= 31/95