GMAT PowerPrep Question 3 - Practice Exam

[weipei]

Can someone explain how to get this answer? Thank you!!!

For a finite sequence of nonzero numbers, the number of variations in sign is defined as the number of pairs of consecutive terms of the sequence for which the product of the two consecutive terms is negative. What is the variation in sign for the sequence 1, -3, 2, 5, -4, -6?

o One
o Two
o Three
o Four
o Five

[mschling52]

I think it's C - three, since

1*-3 = negative
-3*2 = negative
5*-4 = negative

[Cybermusings]

For a finite sequence of nonzero numbers, the number of variations in sign is defined as the number of pairs of consecutive terms of the sequence for which the product of the two consecutive terms is negative. What is the variation in sign for the sequence 1, -3, 2, 5, -4, -6?

A)One
B)Two
C)Three
D)Four
E)Five

Three
(1,-3), (-3,2), (5,-4)

[weipei]

Thanks you guys!