The answer you are looking for is B. 15
Fractions can be added and subtracted but only if they are like fractions or have a common denominator
you will have 1/4 or 25% probability to pick a black sock because
4 blue socks + 5 gray socks + 3 black socks = 12 socks. but you need to pick one of the 3 black socks so 3 out of 12 or 3/12. simplify to 1/4
None, he doesn't have any friends.
