A smoothie recipe uses a number 4 scoop of Greek yogurt, a number 8 scoop of frozen strawberries, and a number 8 scoop of fresh blueberries for 450 smoothies. How many gallons of Greek yogurt are needed?

• A. 28 gallons
• B. 112 gallons
• C. 113 gallons
• D. 29 gallons

Answer: (D)

Scaling the recipe and converting units. First find the total amount of Greek yogurt in scoops: 4 scoops per smoothie times 450 smoothies equals 1800 scoops. If a scoop is 1/4 cup (a common kitchen size), that’s 1800 × 1/4 = 450 cups of yogurt. Converting cups to gallons, since 1 gallon = 16 cups, 450 cups ÷ 16 = 28.125 gallons. In practice you’d round up to ensure you have enough, so you’d plan for 29 gallons of Greek yogurt.