Question

how would you write this word problem as an equation? When the gas gauge on her car was on the 3/8 mark, Karen pumped 15 gal. of gas into the tank in order to fill it. How many gal. of gas does the tank in Karen's car hold?

Answer 1

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