vinod_ece66 wrote:how can this be solved?
If x is a positive number, is x greater than 1?
(1) 1> 1/x
(2) -1/x > -1
From (1) 1> 1/x:
we know x is positive, so if we multiply both sides of the inequality by x, we don't need to reverse the inequality. This gives: x > 1. Sufficient.
From (2) -1/x > -1
we know x is positive, so if we multiply both sides of the inequality by x, we don't need to reverse the inequality. This gives -1 > -x. Now we multiply both sides by -1, but since we're multiplying by a negative, we need to reverse the inequality. This gives 1 < x. Sufficient. (Alternatively, you could have multipled by -1 at the beginning, and noticed that this gives you the same info as statement 1)
D.
