Question

The Directions for mixing an insect spray say to use 2 3/4 ounces of chemical in each gallon of water. How many ounces of chemical should be mixed with 7 4/5 gallons of water?

Answer 1

(2 3/4) / 1 = x / (7 4/5) =
(11/4) / 1 = x / (39/5) =
cross multiply
(1)(x) = (11/4 * 39/5)
x = 429 / 20
x = 21.45 or 21 9/20 oz. <==