Help plz will mark brainilest

(hurry! ) which expression is equivalent to the following complex fraction?

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?

When 142 is added to a number the result is 64 more then 3 times the number. option 35 37 39 41