Determining the probability from the given ball situation.

A box contains 7 red, 3 green and 5 blue balls.

a) If one ball is drawn at random, find the probability it is red.

b) If two balls are drawn, find the probability both are green

c) If two balls are drawn, find the probability one is red and the other is blue

d) If two balls are drawn, find the probability both are red or both are green.

e) If two balls are drawn, find the probability at least one is red.