Answer :
If the tank was 3/8 full, then it was 5/8 empty.
It took 15 gallons to fill those empty 5/8 of a tank.
5/8 x (1 tank) = 15 gallons
1 tank = 15 / (5/8) = 15 x 8/5 = 24 gallons
It took 15 gallons to fill those empty 5/8 of a tank.
5/8 x (1 tank) = 15 gallons
1 tank = 15 / (5/8) = 15 x 8/5 = 24 gallons