A complex Engineering system is composed of five subsystems. Each of these subsystems is independent of the other four. The lifetime, in hours, of...

A complex Engineering system is composed of five subsystems. Each of these subsystems is independent of the other four. The lifetime, in hours, of each of these subsystems is given by:

f(x)= { 0 if x ≤ 100, 100/x^2 if x > 100

What is the probability that exactly 2 out of the 5 subsystems in this complex system, will have to be replaced within the first 150 hrs. of operation?