GRE General TestQuantitative ReasoningMedium
A chef is preparing a large batch of soup. The recipe calls for 2.5 cups of broth for every 3 servings. If the chef needs to make 36 servings, how many cups of broth will be required?
- A25 cups
- B30 cups
- C32.5 cups
- D20 cups
Show answer & explanationAnswer & explanation
Correct answer: B. 30 cups
First, find the number of 'batches' of 3 servings needed: 36 servings / 3 servings/batch = 12 batches. Then, multiply the broth per batch by the number of batches: 2.5 cups/batch * 12 batches = 30 cups.
Why the other options are wrong
- A. This would be 2.5 * 10, implying 30 servings, not 36.
- C. This is a plausible distractor, likely from a miscalculation.
- D. This is a plausible distractor, perhaps from an incorrect ratio or calculation error.
Proportional Reasoning (Unit Rate)
Solving problems by establishing a constant ratio (unit rate) between two quantities and using it to find an unknown quantity.
- Identify the given ratio (e.g., cups per serving).
- Determine the unit rate (quantity per 1 unit).
- Multiply the unit rate by the desired total units.
Memory trick: Find the unit for one, then scale it up, your recipe's done!