A tricky one

This topic has expert replies
Master | Next Rank: 500 Posts
Posts: 133
Joined: Sat Dec 29, 2007 2:43 am
Thanked: 12 times

A tricky one

by raju232007 » Fri Oct 03, 2008 3:30 am
Is x>y?

1.sqrt(x)>y
2.x^3>y

The ans is C..Can you explain this one?

Master | Next Rank: 500 Posts
Posts: 198
Joined: Fri Mar 09, 2007 8:40 pm
Thanked: 7 times

by kris610 » Fri Oct 03, 2008 8:50 am
A) X could be a +ve fraction, in which case sqrt(X) maybe > Y.
x=16 y=1/5 sqrt(X) > Y, but X < Y.

X and Y could be +ve integers, in which case X > Y. Not Sufficient.

We don't have to bother about -ve numbers here as sqrt is involved.

B) X and Y could be +ve integers, in which case X > Y.
X can be a -ve fraction. X =-1/2 Y=-1/5 X^3>Y, but X < Y.

If Y is a -ve integer, X could be a -ve fraction for this condition and X > Y.

Not sufficient.

A and B tell you that X and Y have to +ve integers and X > Y.