GMAT Focus EditionQuantitative ReasoningMedium
A chef is preparing a special blend of spices. He has three types of spices: Spice A, Spice B, and Spice C. He needs to mix them in the ratio of 3:2:5 by weight, respectively. If he uses 150 grams of Spice A, what is the total weight of the spice blend?
- A300 grams
- B500 grams
- C250 grams
- D450 grams
Show answer & explanationAnswer & explanation
Correct answer: B. 500 grams
The given ratio 3:2:5 for Spices A, B, and C means that for every 3 parts of Spice A, there are 2 parts of Spice B and 5 parts of Spice C. If 3 parts correspond to 150 grams, then one part is 50 grams. The total number of parts is 3+2+5=10, so the total weight is 10 parts * 50 grams/part = 500 grams.
Why the other options are wrong
- A. This is the combined weight of Spice A and Spice B (3+2=5 parts * 50g/part).
- C. This would be the total if 1 part was 25 grams.
- D. This is the weight of Spice C (5 parts * 50g/part = 250g) plus Spice A (150g).
Ratios and Proportions
A ratio compares two or more quantities, while a proportion states that two ratios are equal. Ratios are often used to define relationships between parts of a whole.
- Ratios can be simplified by dividing by a common factor.
- To find actual quantities from a ratio, use a common multiplier.
- Proportions are useful for scaling recipes, mixtures, or maps.
Memory trick: Ratios Connect Parts, Proportions Scale.