Question

The time (t) required to empty a tank varies inversely as the rate (r) of pumping. If a
pump can empty a tank in 3 hours at a rate of 400 gallons per minute, how long will it
take to empty a tank at 600 gallons per minute?

Answer 1

Answer:

T = C / R      t = time, C =constant of proportionality, R = rate

180 min = C / 400 gal/min      

C = 72000 gal      to empty tank

T = 72000 gal / 600 gal/min = 120 min = 2 hrs