og-ds-190

diatomss

An infinite sequence of positive integers is called an "alpha sequence" if the number of even integers in the sequence is finite. if S is an infinite sequence of positive integers , is S an alpha sequence?

(1)the first ten integers in S are even

(2)an infinite number of integers in S are odd

答案是E.

我不了解这题的意思,请各位大侠帮忙.

谢谢~~

fhhrewr

如果一个无穷数列含有的偶数个数是有限的，那么这个数列就叫做 alpha sequence

由1）不能推出剩下的数是否含有无穷多个偶数

由2）S里有无穷多个奇数，仍然推不出偶数是否是有限个

1）、2）加起来，还是推不出