Jack's sock drawer contains 10 blue socks and 12 gray socks.  
The room is dark and he cannot turn on the light.  What is 
the least number of socks he must take out of the drawer to 
be certain of each of the following conditions?

a. He has a pair of the same color.
b. He has a pair of the blue socks
c. He has a pair of gray socks.
d. He has one pair of each color.