Can you help me with my math thank you

Little’s law firm has just one lawyer. customers arrive randomly at an average rate of 6 per 8 hour workday. service times have a mean of 50 minutes and a standard deviation of 20 minutes. how long does a customer spend at little’s law firm on average?

Credit card a offers an introductory apr of 3.4% for the first three months and standard apr of 15.7% thereafter,

Select all the expressions that will include a remainder.