AlgebraMediumRange from a fundraising target and a distance limit
Algebra practice question
In a sponsored walk, Sam raises $5 for each kilometre walked. Sam wants to raise at least $120 but can walk at most 30 kilometres. Which inequality describes all possible distances d, in kilometres, that Sam can walk?
- A. 24 ≤ d ≤ 30Correct
- B. d ≥ 24
- C. 24 < d < 30
- D. 5 ≤ d ≤ 30
Answer: A. 24 ≤ d ≤ 30
5d ≥ 120 gives d ≥ 24, and the limit gives d ≤ 30: 24 ≤ d ≤ 30.
Why the other answers are wrong
- B. d ≥ 24
- Omits the 30-kilometre limit.
- C. 24 < d < 30
- Both bounds are inclusive ('at least', 'at most').
- D. 5 ≤ d ≤ 30
- 5 is the rate per kilometre, not a bound on d.
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