If x, y and a are numbers, is x y? 1) x + a x - a;

Question

If x, y and a are numbers, is x > y?
1) x + a > x - a;
2) ax > ay;
Plz explain your answer

AJB77 · Answer

C

x+a > x-a => a > -a or a > 0

If a >0 and ax > ay, we can divide by a and get x > y

vivek123 · Answer

Agree with 'C'.

i) Does not tell anything about 'x' & 'y' relation, but it tells 
 that a > 0.

ii) Not sufficient, since it can mean x>y or x < y, depending on 
 'a'.

Together solve the problem, a > 0 & ax > ay => x > y.

ywilfred · Answer

From 1, we can't tell anything since we have no information about y. So statement 1 is not sufficient.

From 2, we have x>y is a is positive, or x<y is a is negative. So we can't solve again.

Using statement 1, we can solve the inequality as:

2a > 0
a > 0

So a is a positive number. This information, plus using statement 2, we know x > y. 

The answer is therefore C

qpoo · Answer

C

1) x + a > x - a; => a > 0
2) ax > ay; with 1) => x > y

If x, y and a are numbers, is x > y? 1) x + a > x - a;

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