Two hoses are used to fill the pool. Twice as many gallons
of water per minute flow through one of the hoses
as through the other. Both hoses had been on for
12 hours and had filled the pool to the 4-foot mark
when the hose with the faster flow stopped working.
The hose with the slower flow then finished filling the
pool to the 5-foot mark. Which of the following graphs
shows the relationship between the time spent filling
the pool and the height of the water in the pool?