A system with three independent components works correctly if at least one

component is functioning properly. Failure rates of the individual components are λ1

= 0.0001, λ2 = 0.0002, and λ3 = 0.0004 (assume exponential lifetime distributions).

(a) Determine the probability that the system will work for 1000 hours.

(b) Determine the density function of the lifetime X of the system.

How do i solve this please help me.