probability

Question

An insurance company writes policies for a large number of newly-licensed drivers each year. Suppose 40% of these are low-risk drivers, 40% are moderate risk, and 20% are high risk. The company has no way to know which group any individual driver falls in when it writes the policies. None of the low-risk drivers will have an at-fault accident in the next year, but 10% of the moderate-risk and 20% of the high-risk drivers will have such an accident. If a driver has an at-fault accident in the next year, what is the probability that he or she is high-risk?

Answer 1

Out of 100 drivers...20%*20%*100 = 4 are high risk drivers with accidents

                             40%*10%*100 = 4 are moderate risk drivers with accidents

 

So if a driver has an accident, he/she is part of those 8 people. Chances are 50% he/she is from the high risk pool.