Bunuel wrote:

Is positive integer x prime?

(1) x^2 has exactly three factors

(2) x^3 has fewer than five factors

Kudos for a correct solution.

1) If \(x^2\) has exactly 3 factors, the x must be a prime number. Factors of \(x^2\) would be 1, x, and \(x^2\). Pick 2. \(x^2\)=4. Factors are 1, 2, 4.

2) if you take a prime number, then the total number of factors of \(x^3\) is 4, but if you take 1, which is positive but not a prime number the number of factors is also smaller than 5. Not sufficient.

Answer A.

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