请教高人og绿皮上problem solving 54题和169题

请那位高人翻译下这句话吧，连意思都没有看懂。。。。

54.in the table above, what is the least number of table entries that are needed to show the mileage between each city ang each of the other five cities?

A) 15

B) 1

C) 5

D) 0

E) 6

169. if n is a positive integer and n2(平方) is divisible by 72, then the largest positive integer that must divide n is

a) 6

b) 12

C) 24

D) 36

E) 48

.in the table above, what is the least number of table entries that are needed to show the mileage between each city ang each of the other five cities

在上述表格里，最少所需要的表格入口数目，这个入口显示了从一个城市到另外五个城市之间里程的距离。

so 定义一下什么叫表格入口数目？