The pool has 60 inches of water in it. It is draining at a rate of 8 inches per hour. How long will it take for the pool's level to be at 20 inches?

Question

Identify the independent and dependent variables, write the function in function notation, and use the function to solve the problem.

Answer 1

From 60 inches to 20 inches is 40 inches that the pool will drain. It drains at the rate of 8 inches per hour. You want to know how long it will take to drain that 20 inches.

Use the ratio 8 inches = 40 inches

1 hour x hours

Cross multiply and you get 8x = 40 Divide both sides by 8 to get x = 5 hours.

It will take 5 hours for the pool to drain 40 inches.

Answer 2

The pool will drain 40 inches to go from 60 inches to 20 inches.

It drains 8 inches per hour, so it will take 40 inches * 1 hour = 5 hours to drain from 60 to 20 inches

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8 inches