a recipe calls for 10 tablespoons of milk for every 21 cups of flour. If the chef puts in 168 cups of flour how many tablespoons of milk does the chef have to put in
x = tablespoons of milk
Proportion:
21 cups of flour / 10 tablespoons of milk = 168 cups of flour / x tablespoons of milk
21 / 10 = 168 / x
Cross multiply
21 ∙ x = 10 ∙ 168
21 x = 1680
Divide both sides by 21
x = 1680 / 21 = 21 ∙ 80 / 21 = 80
80 tablespoons of milk