Acertain system can experience three different types of defects. let ai (i = 1,2,3) denote the event that the system
has a defect of type i. suppose that
p(41) = 0.31, p(a2) = 0.34, p(a3) = 0.4,
p(a, u a2) = 0.58, p(a1 u a3) = 0.62,
p(a2 u az) = 0.65, p(a, na az) = 0.01
(a) find the probability that the system has exactly 2 of the 3 types of defects.
(b) find the probability that the system has a type 1 defect given that it does not have a type 2 or type 3 defect.

with part b plzzz