- A parking garage charges $3 for the first hour and $1.50 for each additional hour or part thereof. If someone parks for 4 hours and 20 minutes, and then receives a 15% discount for being a frequent customer, what is the final parking fee?
Answer: $7.65
Parking time: 4 hours 20 minutes = 4.33 hours. First hour: $3. Additional time: 3 hours 20 minutes = 3.33 hours, which counts as 4 additional hours (since any part of an hour counts as a full hour). Additional cost: 4 × $1.50 = $6. Total before discount: $3 + $6 = $9. After 15% discount: $9 × 0.85 = $7.65. Choice B ($8.50) might result from not applying the discount. Choice C ($9.00) is the pre-discount amount. Choice D ($10.20) might come from miscounting the additional hours as 5 instead of 4.
- Maria is saving money for a bicycle that costs $180. She already has $45 and plans to save $15 each week. However, she also spends $3 each week on bus fare to get to her job. After how many weeks will she have enough money to buy the bicycle?
Answer: 12 weeks
Maria needs $180 - $45 = $135 more. Each week she saves $15 but spends $3, so her net savings is $15 - $3 = $12 per week. To save $135 at $12 per week: $135 ÷ $12 = 11.25 weeks. Since she can't save for a fraction of a week, she needs 12 full weeks. Choice A (10 weeks) assumes no bus fare deduction. Choice B (11 weeks) doesn't account for the partial week. Choice D (13 weeks) likely includes an arithmetic error.
- A recipe calls for 2.5 cups of flour to make 12 cookies. If Jennifer wants to make 30 cookies and flour costs $0.08 per cup, how much will she spend on flour? Round to the nearest cent.
Answer: $0.50
To make 30 cookies from a recipe that makes 12 cookies, Jennifer needs to scale up by a factor of 30/12 = 2.5. Flour needed: 2.5 cups × 2.5 = 6.25 cups. Cost: 6.25 × $0.08 = $0.50. Choice A ($0.48) might result from using 6 cups instead of 6.25. Choice C ($0.52) could come from rounding errors. Choice D ($0.60) might result from using 7.5 cups (incorrect scaling factor of 3).
