both answer and explaination needed A math professor uses on

both answer and explaination needed

A math professor uses one of the two available overhead projectors - A and B. Projector A breaks down with a probability of 20%, while projector B breaks down with a probability of 40%. On Monday, the professor chose a projector at random, and it broke down. What is the probability that it was projector A? 1/3 2/5 1/2 3/5 2/3 none of the others

Solution

P(S) = Probability of drawing from Sample space = 1

p(E) = Probability of Drawing From A : 0.2

therefore probablity that it was of A = 0.2/1 = 0.2 therefore =2/5 = B