Question

Between 9 pm and 6:36 am, the water level in a swimming pool decreased by 6/35 in. Assuming that the water level decreased at a constant rate, how much did the water level drop each hour?

Answer 1

First, we need to know the total hours from 9 pm to 6:36 am.

We have that from 9:00 pm to 6:00 am are 9 hours. We still have 36 minutes.

And

`36\min \cdot(1hour)/(60\min )=0.6hour`

Then, the total hours are 9.6 hours.

The water level decreased by 6/35 in. Then:

`d=\frac{(6)/(35)in}{9.6\text{hour}}\Rightarrow d=0.01786in/\text{hour}`

Then, the level decreased approximately 0.01786 in/hour at that period of time (the water level decreased at a constant rate).