GMAT Prep Quest

[Thouraya]

If k is not equal to 0,1,or -1, is 1/k>0?

1)1/k-1>0
2) 1/k+1>0

The official answer is A, why isn't it D? Thanks

[kevincanspain]

If 1/(k+1) > 0, k+1 > 0 i.e k > -1

We are not to assume that k is an integer, so k could be any real number
between - 1 and 0, or any real number greater than 0 other than 1

[Frankenstein]

If k is not equal to 0,1,or -1, is 1/k>0?

1)1/k-1>0
2) 1/k+1>0

The official answer is A, why isn't it D? Thanks

Hi,
From(2) choose k as any number between -1 and 0.
Let's say k=-0.5, 1/k+1 > 0 but 1/k <0
But if k = 0.5, 1/k+1 > 0 and 1/k >0
Not sufficient

Hence, A