What does 5.3= v-10.7 equal to but show the work

Answer- 0.05 lit of propane fuel will your friend need in order to boil 10 cups of water.

Solution-

The more efficient the stove is ,less the fuel you need to burn.

so efficiency and amount of fuel needed are inversely proportional with each other.

Given

Your stove is 25 percent = 0.25 efficient ,will boil 10 cups of water, using 0.1 lit of fuel .

0.25 × 2 = 0.5 =50 percent efficient stove ,will boil 10 cups of water, using 0.1/2 = 0.05 lit of fuel.

(∵ As multipling a factor of 2 with efficiency will make the amount of fuel needed half.)