Box 1 contains 1000 bulbs of which 10% are defective. Box 2 contains 2000 bulbs of which 5% are defective. Two bulbs are picked from a randomly selected box.

(a) Find the probability that both bulbs are defective.
(b) Assuming that both are defective, find the probability that they came from box 1.


*Not the easiest problem, but very doable for y'all.