The total of a number and -15 equals -6

Aswimming pool has an input pump for filling the pool and an output pump for emptying the pool. the input pump can fill the pool in 3 hours, and the output pump can drain the pool in 5 hours. as you go to bed, the pool is full, but a neighbor’s kid turns on the output pump. at midnight, you awake to find the pool half empty. immediately, you turn on the input pump, but you are sleepy and forget to turn off the output pump. at what time will the pool become full?

Sole with work in 10 years, the average number of hours of tv watched per week by teenagers dropped from 23.9 to 21.4. find the percent of change.

An ant travels at a constant rate of 30cm every 2 minutes.at what speed does the ant travel per minute