Multi-Operation Problems
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SSAT Upper Level: Quantitative › Multi-Operation Problems
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?
10 weeks
13 weeks
12 weeks
11 weeks
Explanation
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.
$0.48
$0.50
$0.52
$0.60
Explanation
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).
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?
$7.65
$8.50
$9.00
$10.20
Explanation
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.