GRE数学竟然还会考甘特图！！！学而思考满分在线课堂

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> GRE数学竟然还会考甘特图！！！

GRE数学竟然还会考甘特图！！！

2021-06-22 20:16:42

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最近GRE数学怪题偏题频频出现，冷门的考点开始逐渐加入到考试中来，难倒了不少杀G同仁。比如今天要讲的“甘!特!图! ”有些同学看到这几个字就会问，甘特什么？甘什么图？什么特图？

没关系，我们一起跟这个甘特图过过招！先来看看下面这几道题：

Questions 4 to 6 are based on the following data.

Each of the15 customers who arrived at a customer service desk between 9 AM and 10 AM was served in order of arrival by one of the two customer service representatives. Each representative served one customer at a time and finished with that customer before serving any other customers. The graph shows the waiting and service times, recorded to the nearest minute, for customers numbered 1 to 15.

Of customers 4, 6, 8, 9 and 10, which one was served by the customer service representative who served customer 1?

A. Customer 4

B. Customer 6

C. Customer 8

D. Customer 9

E. Customer 10

According to the recorded times, which customer had the greatest ratio of waiting time to service time?

A. Customer 6

B. Customer 7

C. Customer 8

D. Customer 9

E. Customer 15

What was the range of the recorded service times, in minutes, for the 15 customers?

A. 4

B. 6

C. 7

D. 9

E. 14

是不是已经看懵了？其实这道题很简单，不信，宁来康康：

我们先把题干信息整理一下

客户按照先来后到的顺序被服务，每个客户代表每次只能服务一个人，这个客户离开之后才能开始服务下一个客户。

我们再把图的信息整理一下

发现9:00-9:15中间，刚好隔了三个大的竖格，那每个竖格不就刚好是5 minutes嘛，一个大的竖格又分成了5个小的竖格，那每个小的竖格不就是1 minute嘛。

整理完了这些信息之后，做这些题简直就如履平地啦。

问服务了第一个客户的客户代表，又服务了下面哪一位客户。

假设服务了第一个客户的客户代表是甲，我们又已知他服务完这个客户才能服务下一个客户。那我们就可以来快乐地数格子就行了。1号服务完了之后，刚好3开始了，就说明甲服务的第二个客户是3号，3结束了之后是5开始，5结束了之后是7开始，7结束了之后是10开始。所以被甲服务的客户就是3、5、7、10这几个。那么答案就选E。So easy！