Question

A river is rising at a rate of 3 inches per hour. If the river rises more than 2 feet, it will exceed flood stage. How long can the river rise at this rate without exceeding flood stage?

Answer 1

There are 24 inches in 2 feet. Every hour it rises 3 inches. So 24/3=8. It can rise for 8 hours before exceeding flood stage.

Answer 2

Answer: 8 hours.

Explanation:

Given:- A river is rising at a rate of 3 inches per hour.

⇒ In one hour, the increase in the level of river= 3 inches

If the river rises more than 2 feet, it will exceed flood stage.

⇒ the level of river must be less than 2 feet

We know that, 2 feet=2×12 inches [1 foot= 12 inches]

⇒ 2 feet = 24 inches

Thus time taken to rise at the same rate without exceeding flood stage

= i.e. Time taken to reach 24 inches=
`(24)/(3)`

= 8 hours.