Assume that a construction activity has an uncertain duration (D) for competition. The duration was subjectively evaluated based on prior experiences with similar activities as an interval with a uniform distribution with a = 100 and b = 200 days. Determine the following probabilities:

(a) P(D >

100);

(b) P(D < 150);

(c) P(D = 180); and

(d) P(120 < D < 200).