请教一道GMAT数学题目

zyzhengyao

For a finite sequence of nonzero numbers, the number of variations in sign is definded as the number of pairs of consecutive terms of  the sequence for which the product of the 2 consecutive terms is negative.

what is the number of variation in sign for the sequence 1, -3, 2, 5, -4, -6.

请问这个题目的确切含意和解题思路？

FlowerJay

俺直接翻译一下，这个是说number of v， 就是这6个数字中相邻两个数字乘积是负数的数字的对数，这么说应该是 (1,-3) (-3,2) (5,-4)答案是3么？

poem_laurel

如果 "consecutive terms of  the sequence " 意味着数集应表示为 -6 -4 -3 1 2 5

只有一对(-3 1)

夏天不热

我觉得应该是 3

如果按照排序以后再算的话，无论这个Sequence里面有哪些数，答案只会是1或者0吧？

For instance:

-6 -4 -3 1 2 5

-10 -7 -5 3 4 6

1 3 4 6 7

jesse122

应该是3吧

就是连续的两个数字成绩为负

就是1,-3;-3,2;5,-4