Help please!! don’t have to show work just tell me where to put the parentheses

Marcus built a model car that is 4 inches wide. what scale was used to build the car if the actual width of the car is 6 feet? a. 1 in. = 2 ftb. 1 in. = 2.5 ftc. 1 in. = 1.5 ftd. 1 ft = 1.5 in.

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?

For the rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. for an 10 month period, the last term is and the series sum is . for a 15 month period, the last term is and the series sum is . for a 20 month period, the last term is and the series sum is