Whats the answer for this one? urgently need correct answers

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?

Acomputer store bought a program at a cost of $10 and sold it for $13. find the percent markup

Kira looked through online census information to determine the overage number of people living in the homes in her city what is true about kira's data collection?