# Shima will mix 1 fluid ounce of fertilizer in water

Shima will mix 1 fluid ounce of fertilizer in water for every 40 square feet of soil. At this rate, which of the following expressions gives the number of gallons of fertilizer that Shima will mix in water for 0.5 acres of soil?

(Note: 1 acre = 43,560 square feet; 1 gallon = 128 fluid ounces)

1. $$\frac{0.5(40)(128)}{43,560}$$
2. $$\frac{40(128)}{0.5(43,560)}$$
3. $$\frac{0.5(43,560)}{40(128)}$$
4. $$\frac{43,560}{0.5(40)(128)}$$
5. $$\frac{0.5(43,560)(40)}{128}$$