Given that the amount of time varies inversely with G.
It can be written as,

where K is the constant.
We need to determine the time it takes to put out the fire when 200 gallons of water are used.
<u>The value of constant:</u>
When
, we get;


Thus, the value of constant is 96.
<u>Time taken:</u>
Substituting
and
in the formula
, we get;

Thus, the time taken to put out the fire using 200 gallons of water is 48 minutes.
Hence, Option B is the correct answer.