Answer:
9 minutes
Explanation:
The amount of time t that it takes to put out a fire varies inversely with the volume of water used, G
t = k/G
Where,
k = constant
When G is 3, t is 15
t = k/G
15 = k/3
Cross product
15 * 3 = k
k = 45
Find t when G = 5
t = k/G
t = 45/5
t = 9 minutes