Answer:
2/5 gallons
Step-by-step explanation:
If it takes 2 gallons of paint to paint 5 walls, then the amount of gallons used per wall can be calculated by comparison
[tex]5 walls = 2 gallons \\ 1 \: wall = x \: gallons \\ by \: cross \: multiplication \\ 5 \times x = 2 \times 1 \\ 5x = 2 \\ x = \frac{2}{5} [/tex]
Hence, 2/5 gallons of paint is used per wall.