AlgebraEasy–MediumTwo numbers from a sum and a multiple condition
Algebra practice question
The sum of two numbers is 13, and three times the smaller number equals the larger number plus 3. What is the smaller number?
- A. 4Correct
- B. 9
- C. 5
- D. 3
Answer: A. 4
Let the numbers be s and l: s + l = 13 and 3s = l + 3. Substituting l = 13 − s gives 3s = 16 − s, so 4s = 16 and s = 4.
Why the other answers are wrong
- B. 9
- 9 is the larger number.
- C. 5
- 5 comes from 4s = 20, adding 3 to 13 twice.
- D. 3
- 3 comes from 3s = l + 3 read as 3s = 3 + 3 + 3.
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