A local bank branch employs three tellers who can each help a customer on average in 6 minutes, with a standard deviation of 3 minutes. On average, 24 customers arrive at this bank per hour (in a random fashion). How long would customers have to wait if we do not pool the employees? (By "not pooling," we mean we have 3 separate lines forming; one in front of each of the 3 tellers. Assume that a person randomly enters one of the lines - each of the 3 lines takes one-third of the arrivals - and a person does not switch lines after entering a line.)