I've taken stats a few years back and this is a requirement for my concentration. Any help is appreciated A small factory contains 3 machines (A, B, C) that produces defective and non-defective parts. It's known that: (i) 40% of all parts are produced on machine A; (ii) 20% of all parts are produced on machine C; (iii) 15% of all parts are defective; (iv) 20% of the defective parts were made on machine C; (v) 75% of the parts made on machine A are non-defective. So my question is, what is the probability that a part was either produced on machine A or is defective? According the manual, the answer is 0.45 but I'm trying to figure out how that answer came about.
0.4 + .15 - 0.1 = 0.45 ie. probability of a part produced on machine A + probability of a defective part - probability of being both
