Question

A tank measure 30 centimeters by 30 centimeters by 50 centimeters. It is filled with water from a tap that flows at a rate of 6 liters per minute. How long would it take to fill 4/5 of the tank with water? Give your answer in minutes and seconds.

Answer 1

6 minutes

Explanation:

There are two ways you can simplify this problem:

1. change the dimensions to 3 dm × 3 dm × 5 dm, because 1 L = 1 dm³

2. Adjust the 5 dm dimension to 4/5 that value: 4 dm. Then you're filling a whole volume that is 3 dm × 3 dm × 4 dm = 36 dm³ = 36 L.

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At the rate of 6 L/min, the tank will be filled to the desired level in ...

(36 L)/(6 L/min) = 6 min . . . . and 0 seconds

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A decimeter is 0.1 m = 10 cm, so 1 cubic decimeter is (10 cm)³ = 1000 cm³ = 1 liter. Using decimeters as the unit of measure in volume problems can make conversion to liters trivial.