AlgebraEasy–MediumSolving a two-variable equation in context
Algebra practice question
A café sells muffins for $3 and scones for $2. The equation 3m + 2s = 18 relates the numbers of muffins m and scones s bought for exactly $18. If 4 muffins are bought, how many scones are bought?
Answer: 3
Substitute m = 4: 12 + 2s = 18, so 2s = 6 and s = 3.
Common wrong answers
- If you answered 2
- 2 comes from 12 + 2s = 18 solved as 2s = 4.
- If you answered 6
- 6 is 2s, the money spent on scones, not the number.
- If you answered 9
- 9 is 18/2, ignoring the muffins.
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