Is x an integer?

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Source: — Data Sufficiency |

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by [email protected] » Sat May 11, 2019 12:37 pm

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Hi All,

We're asked if X is an INTEGER. This is a YES/NO question. This question is built around some standard math rules and Number Properties.

(1) X^3 = 8

With Fact 1, we're cubing the value of X and ending with a POSITIVE value - thus, X MUST be positive. Here, the value of X = +2 and the answer to the question is YES.
Fact 1 is SUFFICIENT

(2) X =√4

With Fact 1, we have a number that's square-rooted for the value of X. The square root of a number has just ONE solution: a POSITIVE one. Here, we're dealing with the positive square-root of 4, so the value of X = +2 and the answer to the question is YES.
Fact 2 is SUFFICIENT

Final Answer: D

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