Posted by pankaj on .
(ii) A factory has two machines. Past records show that the first machine produces 40% of output and the second machine produces 60% of output. Further 4% and 2% of the products produced by the first machine and the second machine were defectives. If a defective item is drawn at random, what is the probability that the defective item was produced by the first machine or second machine?

math1 
Damon,
say we make 1000 total
400 from #1, 16 defective
600 from #2, 12 defective
Tat is a total of 28 defective
16/28 = .57 from #1
12/28 = .43 from #2