Question

10. The time it takes to drain a swimming pool varies inversely with the amount of water being

pumped per hour. If a large pool takes 12 hours to empty at 400 gallons an hour, how many
hours faster can the pool be drained if the pumping rate is increased to 500 gallons per hour?
(teal)

Answer 1

To solve this problem, we can use the formula for inverse variation, which is:

time = k/ rate

where k is a constant of proportionality.

We can start by finding the value of k using the given information. We know that when the pumping rate is 400 gallons per hour, it takes 12 hours to drain the pool. Therefore:

12 = k/400

Multiplying both sides by 400 gives us:

k = 4800

Now we can use this value of k to answer the second part of the question. We want to know how many hours faster the pool can be drained if the pumping rate is increased to 500 gallons per hour. Let's call this new time t:

t = 4800/500

t = 9.6 hours

So the pool can be drained 12 - 9.6 = 2.4 hours faster if the pumping rate is increased to 500 gallons per hour.