The time t (in hours) that it takes a pump to empty a tank of water varies inversely with the pumping rate r (in gallons per hour). if it takes 9 hours to empty a tank of water when the pumping rate is 60 gallons per hour, how long does it take to empty the tank when the pumping rate is 180 gallons per hour?

Step-by-step explanation:

The time t (in hours) that it takes a pump to empty a tank of water varies inversely with the pumping rate r (in gallons per hour).

where k is a constant.

It takes 9 hours to empty a tank of water when the pumping rate is 60 gallons per hour.

We need to find how long does it take to empty the tank when the pumping rate is 180 gallons per hour ( r = 180)

We have

It takes 3 hours to empty the tank when the pumping rate is 180 gallons per hour.