AlgebraMediumGreatest whole number satisfying a limit
Algebra practice question
A lift can carry at most 600 kilograms. A worker who weighs 80 kilograms rides the lift with some boxes, each weighing 25 kilograms. What is the greatest number of boxes the worker can take in one trip?
Answer: 20
80 + 25b ≤ 600, so 25b ≤ 520 and b ≤ 20.8. The number of boxes is a whole number, so the greatest is 20. Check: 80 + 500 = 580 ≤ 600; 21 boxes would make 605.
Common wrong answers
- If you answered 21
- 21 rounds 20.8 UP, but 21 boxes plus the worker weigh 605 kg, over the limit. Round down.
- If you answered 24
- 24 is 600 / 25, forgetting the worker's 80 kg.
- If you answered 27
- 27 is (600 + 80) / 25 — the worker's weight was added to the limit instead of subtracted from it.
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