In a process that manufactures aluminum cans, the probability that a can has a flaw its side is 0.02, the probability that a can has a flaw on the top is 0.03, and the probability that a can has a flaw on both the side and the
top is 0.01. What is the probability that a randomly chosen can has a flaw? What is the probability that it has no flaw?
Solution
We are given that P(flaw on side) = 0.02, P (flaw on top) = 0.03, and P(flaw on side and flaw on top) = 0.01. Now P(flaw) = P(flaw on side and flaw on top). Using Equation(2.5),
P(flaw on side and flaw on top) = P(flaw on side) + P(flaw on top)
– P(flaw on side and flaw on top)
= 0.02 + 0.03 + 0.01
= 0.04
To fine the probability that a can has no has no flaw, we compute
P(no flaw) = 1- P(flaw)
= 1- 0.04
= 0.69