Gmat prep basic inequility
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Given that xy=-18, both x & y cannot be simultaneously positive or negative. Both of them would be of opposite nature.
now, statement 1 says, x<0, then y needs to be positive. Thus, y>x. Hence A alone is sufficient.
Now, considering statement 2, y<10, Lets consider following two cases wherein y is less than 10:
case 1: y=9 and x=-2
Case 2: y=-2 and x=9
Both these cases result in xy=-18 and in both the cases y<10. However, we cannot conclude whether x<y or not. Thus, statement 2 alone is not sufficient.
Thus, the answer is A
now, statement 1 says, x<0, then y needs to be positive. Thus, y>x. Hence A alone is sufficient.
Now, considering statement 2, y<10, Lets consider following two cases wherein y is less than 10:
case 1: y=9 and x=-2
Case 2: y=-2 and x=9
Both these cases result in xy=-18 and in both the cases y<10. However, we cannot conclude whether x<y or not. Thus, statement 2 alone is not sufficient.
Thus, the answer is A