Question

Difficulty: EasyRatios, Rates, and Proportions

A recipe for fruit punch calls for orange juice and cranberry juice to be mixed in a ratio of 3:43:4. If a chef uses 1212 cups of orange juice, how many cups of cranberry juice should be used?

  1. A
    4
  2. B
    9
  3. C
    13
  4. 16Answer
  5. E
    28

Answer

16 cups
Since the ratio of orange juice to cranberry juice is 3 to 4, we can set up the proportion 3/4 = 12/x, where x is the amount of cranberry juice. Solving for x yields 16 cups.

Step-by-Step Solution

1
Set up a proportion based on the ratio of orange juice to cranberry juice.
34=12x\frac{3}{4} = \frac{12}{x} where xx represents the number of cups of cranberry juice.
The ratio of orange juice to cranberry juice is constant at 3 to 4.
2
Solve the proportion for xx by cross-multiplying.
3x=12×43x = 12 \times 4
3x=483x = 48
Cross-multiplication is a standard method to solve proportions.
3
Divide both sides by 3 to isolate xx.
x=16x = 16
Isolating the variable gives the required amount of cranberry juice.

Key Concept

Solving a part-to-part ratio problem using proportions.
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