Integer ?s

[imadummy]

Help...

If x and y are integers, what is the value of y?

(1) xy = 27
(2) x = y^2

Answer [c] (?)

[rattanas]

Yes the answer should be c..as 1 and 2 alone are not sufficient...to solve it would be like y^3=27..so y =3

[VP_RedSoxFan]

(1) This statement narrows the value of y to {1, 3, 9, 27} but obviously not a single value like we're looking for so its insufficient.

(2) x = y^2. The most tempting thing about this one is if you let knowledge and information from (1) bleed onto it. This actually doesn't limit y to anything other than y^2 being an integer or, rather, that y is the square root of x.

Combining the two, however gets us there because (1) limits our choices to {1, 3, 9, 27} and (2) limits our possibilities to perfect square roots. In that set of available choices, only 3 is the square root of another factor of 27.

Ans: [C]

[imadummy]

While I'm a Yankees fan, I appreciate the clear solution you gave RedSox man.