John is filling a bathtub that is 18 inches deep. He notice the it takes two minutes to fill the tub with three inches of water. He estimates it will take ten more minutes for the water to reach the top of the tub if it continues at the same rate. Is he correct. Explain.

In the given question, all the information's are already provided for deducing the answer. It is given that the tub is 18 inches deep. In 2 minutes the tub fills up 3 inches and John estimates that the tub will fill up in 10 minutes. Let us put the knowledge gained separately.

The depth of tub still left to be filled = 18 - 3

= 15 inches

We know

3 inches depth of the tub gets filled in = 2 minutes

Then

15 inches depth of the tub will be filled in = (2/3) * 15

= 10 minutes

So we see that the remaining tub will get filled in 10 minutes and John is absolutely correct about his assumption.