AMC数学竞赛8专为8年级及以下的初中学生设计，但近年来的数据显示，越来越多小学4-6年级的考生加入到AMC 8级别的考试行列中，而当这些学生能在成绩中取得“A”类标签，则是对孩子数学天赋的优势证明，不管是对美高申请还是今后在数学领域的发展都极其有利！那么接下来跟随小编来看一下AMC 8的官方真题以及官方解答吧：

Problem 13

Two different numbers are randomly selected from the set  and multiplied together. What is the probability that the product is ?

Solution 1

The product can only be  if one of the numbers is 0. Once we chose , there are  ways we can chose the second number, or . There are  ways we can chose  numbers randomly, and that is . So,  so the answer is .

Solution 2

There are a total of  possibilities, because the numbers are different. We want  to be the product so one of the numbers is . There are  possibilities where  is chosen for the first number and there are  ways for  to be chosen as the second number. We seek .

Problem 14

Karl's car uses a gallon of gas every  miles, and his gas tank holds  gallons when it is full. One day, Karl started with a full tank of gas, drove  miles, bought  gallons of gas, and continued driving to his destination. When he arrived, his gas tank was half full. How many miles did Karl drive that day?

Solution

Since he uses a gallon of gas every  miles, he had used  gallons after  miles. Therefore, after the first leg of his trip he had  gallons of gas left. Then, he bought  gallons of gas, which brought him up to  gallons of gas in his gas tank. When he arrived, he had  gallons of gas. So he used  gallons of gas on the second leg of his trip. Therefore, the second part of his trip covered  miles. Adding this to the  miles, we see that he drove  miles.

以上就是小编对AMC竞赛官方真题以及解析的介绍，希望对你有所帮助，更多AMC真题下载请持续关注AMC数学竞赛网！