Praxis Core Academic Skills for Educators: Mathematics (5733)Number and QuantityMedium
A nutritionist is preparing a special dietary supplement. The recipe requires 2 parts protein powder, 3 parts fiber supplement, and 5 parts vitamin mix. If the total weight of the supplement needs to be 300 grams, how many grams of vitamin mix are required?
- A150 grams
- B90 grams
- C120 grams
- D60 grams
Show answer & explanationAnswer & explanation
Correct answer: A. 150 grams
The total number of parts is 2 + 3 + 5 = 10 parts. The vitamin mix accounts for 5 out of these 10 parts, or 5/10 = 1/2 of the total. So, 1/2 * 300 grams = 150 grams of vitamin mix are required.
Why the other options are wrong
- B. This would be 3/10 of the total, which is the fiber supplement amount.
- C. This results from an incorrect calculation of the total parts or the fraction for vitamin mix.
- D. This would be 2/10 of the total, which is the protein powder amount.
Ratio with Total Quantity
When a total quantity is divided according to a given ratio, first sum the ratio parts to find the total parts. Then, express each component as a fraction of the total parts and multiply by the total quantity.
- Sum all parts of the ratio
- Form a fraction for each component (part/total parts)
- Multiply the fraction by the total quantity
Memory trick: Ratios are shares, Proportions are equal shares.