ive been reading a bit about bayes theorem and the answer to this question has me confused
Two video products distributors supply video tape boxes to
a video production company. Company A sold 100 boxes of which 5 were
defective. Company B sold 300 boxes of which 21 were defective. If a box
was defective, .find the probability that it came from Company B.
The answer given is
has the author of the question calculated that the defective box came from
company A not company b
so the answer should be 0.8076
or have i missed something here?