The reservoir has water injection pipe and water outlet pipe, which can supply water for 40 days. If the water injection pipe flow increases by 20% and the water outlet pipe flow increases by 10%, it can also be used for 40 days. How many days can it supply water without adding water?

Let the capacity of the water tank be x, then the conditions can be known from the topic.

X+ 1 influent/1 effluent =40,

AX+ 1.2 water inflow/1. 1 water outflow =40.

B no water, X+ 1.2 water/1 water =? If you put B in, it will be 44 days.

A math problem stumped me. It takes 5 hours to fill the pool with water and 3 hours to drain it. Can be filled with water and drained for several hours at the same time?