AlgebraMediumFractional coefficients on both sides
Algebra practice question
Three quarters of a number, decreased by 15, equals one third of the number, increased by 5. What is the number?
Answer: 48
Let the number be n: (3/4)n − 15 = (1/3)n + 5. Multiply through by 12: 9n − 180 = 4n + 60 → 5n = 240 → n = 48.
Common wrong answers
- If you answered 12
- 12 is the common denominator, not the number.
- If you answered 24
- 24 comes from 5n = 120, using 10 instead of 20 for the combined constants.
- If you answered -48
- −48 reverses the sign: 5n = 240, not −240.
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