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hariharakarthi: Master | Next Rank: 500 Posts; Posts: 131; Joined: Tue Apr 22, 2008 1:54 pm; Thanked: 3 times; GMAT Score:550

by hariharakarthi » Sat Jul 25, 2009 4:29 pm

If z is a positive integer, is sqrt(z) an integer?
(1) sqrt(xz) is an integer.
(2) x = cuberoot(z)

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Source: Beat The GMAT — Data Sufficiency | Sat Jul 25, 2009 4:29 pm

raghavsarathy: Master | Next Rank: 500 Posts; Posts: 166; Joined: Sat Apr 18, 2009 10:41 pm; Thanked: 9 times; GMAT Score:770

by raghavsarathy » Sat Jul 25, 2009 5:18 pm

IMO - E

The statements are individually not sufficient.

Even if we take the statements together , we will not be able to determine. I solved by taking a few numbers.

Case 1 : x= 2 , z=8 . Statements 1 and 2 are satisfied.
But sqrt(z)= 2(sqrt 2) is not an integer

Case 2: x= 4, z=64 Statements 1 and 2 are satisfied.
And sqrt(z) = 8 an integer.

Hence both statements are not sufficient.

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