Is this a function? Why or why not?

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?

Carli has 90 apps on her phone. braylen has half the amount of apps as theiss. if carli has three timesthe amount of apps as theiss, how many apps does braylen have? let b represent the number of braylen's apps and t represent the number of theiss's apps.

The graph of a quadratic function has a maximum at point (0, 5). the graph contains the point (2, 1). what is another point on the graph?