AlgebraMediumHours from a bill charged in half-hour units
Algebra practice question
A mechanic charges a $45 call-out fee plus $30 for each half hour of work. A customer's bill was $165. How many hours of work were charged?
Answer: 2
165 − 45 = 120 for the work, and 120 ÷ 30 = 4 half hours, which is 2 hours.
Common wrong answers
- If you answered 4
- 4 is the number of half hours, not hours.
- If you answered 5.5
- 5.5 comes from 165 ÷ 30, ignoring the call-out fee.
- If you answered 2.75
- 2.75 comes from 165 ÷ 30 ÷ 2.
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