At Supercuts, washing a customer's hair takes an average of 3.5 minutes with a standard deviation
of 1.2 minutes. Applying conditioner takes an average of 2.1 minutes with a standard deviation
of .75 minutes. Assuming both washing and conditioning can be explained using a Normal
model, what is the probability that to total time to wash and condition a customer's hair will take longer more than 5 minutes?