SAT Math Multiple Choice Question 442: Answer and Explanation
7. A company that makes shoelaces has two machines, both of which run 24 hours a day. The first machine can produce 36,000 shoelaces per day. The second machine can produce 28,800 shoelaces per day. How many more shoelaces can the first machine make than the second machine in 8 minutes?
- A. 5
- B. 40
- C. 160
- D. 200
Correct Answer: B
Category: Problem Solving and Data Analysis / Rates, Ratios, Proportions, and Percentages
Strategic Advice: Let the units in this question, as in most rate questions, guide you to the answer.
Getting to the Answer: The rate at which each machine can produce is given per day, but the question asks about the number of shoelaces each machine can produce in 8 minutes, so convert shoelaces per day to shoelaces per minute and multiply by 8. Then find the difference.
The first machine can produce 200 – 160 = 40 more shoelaces in 8 minutes.