A girl worked last summer. The first week she was there she worked a total of 25 hours in the office. She was paid $13.50 an hour for day shift and $15.50 an hour for night shift work .She earned $373.50 for first week of work . How many hours did she spend on the day shift ? How many hours did she spend on the night shift?
If she worked only on the day shift, her earnings would have been $13.50 * 25 = $337.50. However, her earnings are $373.50 - $337.50 = $36.00 more. Each hour worked on the night shift adds $2 to her earnings, so she worked 36/2 = 18 hours on the night shift and 25 - 18 = 7 hours on the day shift.