og12 86数学请教

ericafdl

A number of people each wrote down one of the fi rst
30 positive integers. Were any of the integers written
down by more than one of the people?
(1) The number of people who wrote down an
integer was greater than 40.
(2) The number of people who wrote down an
integer was less than 70.

这题看了OG的解释也是一头雾水，请高人指点一下思路

fcxir

A
题目说有一些人每个写下1-30之中的一个整数，问有没有一个整数会被不止一个人写
A说人多于40个，只有30个整数，怎么写都会有一个整数会被不止一个人写
B说人少于70，这个就不一定了，如果是50，那么肯定有一个整数会被不止一个人写，如果是20，那就不一定了
所以选A

ericafdl

明白了，这个40和70是指人数而不是指数字！还是读题理解的问题，多谢多谢！