Question

In producing screws, let A mean ‘screw too slim’ and B ‘screw too short’. 

Let P(A) = 0.1 and let the conditional probability that a slim screw is also too short be P(B/A) = 0.2. Then what is the probability that a screw that we pick randomly from the lot produced will be both too slim and too short?

Answer 1

We require the probability of occurrence of both the events together, which can be given as 

P(A ∩ B)= P(A) P(B/A) = 0.1 . 0.2 = 0.02 = 2%