Depth of water in Jeanne's hot tub varies directly with the number of minutes that the faucet is turned on. At 8:15 AM, there is a foot of water in the tub. when will the hot tub have 2.75 feet of water in it?
The question can't be answered.
We know at 8:15 AM the water was 1 foot deep, but we have to
know how long it took to reach that depth.
e.g. If we knew that at 8:00 the tub was empty, we could do it
but that answer would be different if the tub was empty at 7:00, etc
If the depth of water in Jeanne's hot tub varies directly with the number of minutes that the faucet is turned on, then the amount of time it will take for the hot tub to have 2.75 feet of water in it can be calculated by dividing 2.75 feet by 1 foot and multiplying the result by the number of minutes it took for the hot tub to reach 1 foot of water.
Therefore, it will take (2.75/1) x (number of minutes it took for the hot tub to reach 1 foot of water) minutes for the hot tub to have 2.75 feet of water in it.