Please help with question 12 please

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?

Karen is financing $291,875 to purchase a house. she obtained a 15/5 balloon mortgage at 5.35%. what will her balloon payment be? a. $220,089.34 b. $219,112.46 c. $246,181.39 d. $230,834.98

Which expression can be used to determine the slope of the line that passes through the points -6, three and one, -9