Data Sufficiency

You will have to click on the image to see the problem:




Try this one... OA to come after a few cracks at it from the community.[/img]

1) x = -2, y = 1
x^4 > y^4, but x < y
x = 2, y = 1
x^4 > y^4, but x >y

2) x = 1 y = -32
5th Root(x) > 5th Root(y) and x > y
x = 32 y = 1
5th Root(x) > 5th Root(y) and x > y
x = -1 y = -32
5th Root(x) > 5th Root(y) and x > y

IMO B , I think main logic here is to understand significance of sign change with even and odd power

Thanks Jim good one. Correct me if i miss anything.

My answer is B.

This question is testing the Odd Vs Even powers, please correct me if I am wrong

You guys are right, but be careful with exponent inequality DS questions... Always test between 1 and 0 and -1 and 0...

For (2), I tested with those: (32, 243); (-32, -243); (1/32, 1/243); and (-1/32, -1/243). They indicated that (2) was sufficient. However, it took more than 2 mins to execute the tests. Would you recommend any shortcut? Thank you!

My office network isn't allowing the link to be opened
Wish you could have posted the question so that even I could have attempted it.

Sorry... Had a 5th root in the problem so the only way to do it was with an image...

Also... for those who are looking for a quick way to solve this think about the numbers shifting. When you take an odd root of a number it shifts on the number line. Higher if less than -1, Lower if between -1 and 0, Higher if between 0 and 1 and lower if greater than -1.

Even though you do not know the numbers, you can know that you will never get a "cross-over" when these numbers shift. For this reason, B is correct. The difference with A is that you can have positive and negative numbers for x and y because of the even power.

Hope this helps.