One more..

[aninditasivaram2406]

Hi,
Another one from the GMAT Prep...

If x4+y4=100, then the greatest possible value of x is between
a) 0 and 3
b) 3 and 6
c) 6 and 9
d) 9 and 12
e) 12 and 15
Answer – (b)

Thanks,
Anindita
Btw - x4 denotes x raised to the power of 4 and same for y4.

[showoff16884]

X is greatest when Y = 0.

X = 4th root of 100, which is between 3 & 6

(you know x has to be greater than 3, because when x=3, x^4 = 81 and x can't be greater than 6. You only have one option then)