AMC 8 2014 Problem 2
AMC8 2014 年第 2 题
表达式与运算★☆☆☆☆
Paul owes Paula 35 cents and has a pocket full of 5-cent coins, 10-cent coins, and 25-cent coins that he can use to pay her. What is the difference between the largest and the smallest number of coins he can use to pay her?
Paul 欠了 Paula 35 美分。Paula 目前口袋里有一堆 5 美分，10 美分和 25 美分的硬币可以用来还钱，他可用于还钱的最多硬币数目和最少硬币数目的差是多少？
- A.1
- B.2
- C.3
- D.4
- E.5
正确答案 · Correct Answer
E
解析 · Solution
Solution 1
To use the largest number of coins, Paul would use only 5 5-cent coins. Because 35 = 5 ⋅ 7 35=5⋅7, the largest number of coins Paul can use is 7 7. To use the smallest number of coins, Paul would use a 25 25-cent coin and a 10 10-cent coin, for a total of 2 2 coins. The difference between the largest and the smallest number of coins he can use is 7 − 2 = 5 7−2=5. Answer: 𝐸 E .
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