If 6 gallons of gasoline are added to a tank that is already filled to 3/4 of its capacity, the tank is then filled to 9/10 of its capacity. How many gallons does the tank hold?

Question

Suraj Pandey · Accepted Answer

Understand the problemThe tank is initially filled to 3/4 of its capacity. After adding 6 gallons, it is filled to 9/10 of its capacity.
Set up the equationLet the capacity of the tank be C gallons.Initial amount of gasoline = (3/4)CAfter adding 6 gallons, the amount of gasoline = (3/4)C + 6
This is equal to 9/10 of the tank's capacity:(3/4)C + 6 = (9/10)C
Solve for C(3/4)C + 6 = (9/10)CMultiply through by 20 to clear fractions:20 * (3/4)C + 20 * 6 = 20 * (9/10)C15C + 120 = 18C
Subtract 15C from both sides:120 = 3C
Divide both sides by 3:C = 40
ConclusionThe tank holds 40 gallons.