AlgebraMediumCoffee blend mixture
Algebra practice question
A roaster blends beans costing $9 per kilogram with beans costing $14 per kilogram to make 10 kilograms of a blend worth $11 per kilogram. How many kilograms of the $14 beans are in the blend?
Answer: 4
The blend is worth 10 · 11 = $110. With t kilograms at $14 and (10 − t) at $9: 90 + 5t = 110, so t = 4.
Common wrong answers
- If you answered 5
- An even split would price the blend at $11.50; the actual mix is 6 kg and 4 kg.
- If you answered 6
- 6 kilograms is the amount of the $9 beans; the $14 beans make up 4 kg.
- If you answered 20
- 20 is the dollar gap 110 − 90; divide by the $5-per-kg difference to get 4 kg.
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