Question

A town’s water tower holds 1 million gallons of water. During the day,

the tower is only 2
}5
of its full capacity. The tower will be refilled at night, when water
consumption is low, using a pump that pumps water into the tower at a rate of
2000 gallons of water per minute. How long will it take to bring the tower back to
full capacity? Explain how you got your answer. If the town had a pump that only
filled the tank at 500 gallons per minute, how much longer would it take to fill
the tank?

Algebra 1
2-28 Chapter Resource

Answer 1

Time it will take to bring water to full capacity = 300 minutes

Longer it will take if pump is 500 gallons per minute rate = 900 minutes longer

Explanation:

Total Capacity = 1,000,000 gallons (1 mill)

It is full 2/5th, so it is empty:

1 - 2/5th = 3/5th

Now,

3/5th of 1,000,000 = 600,000

So, we need to fill up 600,000 gallons

The pump rate is 2000 gallons per minute, so the time it will take:

600,000/2000 = 300 minutes

If the pump was 500 gallons per minute rate, that would take:

600,000/500 = 1200 minutes

So, it will take:

1200 - 300 = 900 minutes longer