GMAT
问题描述：
GMAT
Each of the integers from 0 to 9,inclusive,is written on a separate slip of blank paper and the ten slips are dropped into a hat.If the slips are then drawn one at a time without replacement,how many must be drawn to ensure that the numbers on teo of the slips drawn will have a sum of 10?
a) 3
b)4
c) 5
d)6
e)7 求中文翻译
答
题干问的是要抽几次才能保证其中任意抽出的2个数字之和是10.假设最坏的情况,抽出的是 0,1,2,3,4,5,这几个数任意2个加起来都不等于10.那么这样一共抽了6次.从第7次开始,抽出的数和前面的相加都等于10.所以选E