A gas tank is 1/4 full. Abby adds 4 gallons and now it is 5/8 full. How many gallons does the tank hold?

Answer 1

let the tank hold x gallons

(1/4)x + 4 = (5/8)x
times everybody by 8
2x + 32 = 5x
-3x = -32
x = 10 2/3 gallons