AlgebraMediumTwo prices from two purchases
Algebra practice question
At a stall, 4 apples and 2 pears cost $22, and 1 apple and 1 pear cost $8. What is the cost, in dollars, of one apple?
Answer: 3
From the second purchase, p = 8 − a. Substitute: 4a + 2(8 − a) = 22, so 2a + 16 = 22 and a = 3. (A pear is $5.)
Common wrong answers
- If you answered 2
- 2 would make a pear $6 and the first purchase $20, not $22.
- If you answered 5
- 5 is the price of a pear.
- If you answered 8
- 8 is the price of an apple and a pear together.
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