In a study of intelligence, the time (in seconds) for a laboratory animal to reach a reward in a maze was found to have probability density function f (t) = 10/t² , t ≥ 10 where 10 seconds is the minimum time to traverse the maze. Find the probability that an animal chosen at random takes

(a) Between 15 and 30 seconds.

(b) More than 15 seconds given that it took less than 30 seconds.