Question: A city's police department plans to enforce speed limits by using radar traps at four different locations. During morning rush hour, the radar traps at locations L1, L2, L3, L4 are operated with probabilities 0.4, 0.3, 0.2, and 0.3, respectively. A person speeding to work has probabilities of 0.2, 0.1, 0.5, and 0.2, respectively, of passing through these locations.
(a) What is the probability the speeding person will receive a speeding ticket?
(b) If the person received a speeding ticket while speeding to work, what is the probability that he/she passed through the radar trap at location L2?