Need assistance with ratios

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?

How many glue sticks are in a basket containing 96 scissors, if the ratio of glue sticks to scissors is 19 to 57.

Maria walks a round trip of 0.75 mile to school every day.how many miles will she walk in 4.5 days