The amount of time t (in minutes) that it takes to put out a fire varies inversely with G, the volume of water used (in hundreds of gallons) when g is 3, t is 15. Find how long it takes to put out a fire when 500 gallons of water (G=5) are used.
A. 15 minutes
B. 9 minutes
C. 25 minutes
D. 1 minute