Answer :
To increase by 60%, you need to multiply the original 15 liters by 1.6. The 1 incorporates the original 15 liters and the 0.6 equals the amount gained.
15×1.6=24 liters (total)
15×0.6=9 liters (amount gained)
15×1.6=24 liters (total)
15×0.6=9 liters (amount gained)
