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What is the value of X? 1. X^4 = |X| 2. X^2 > X 1. X is {-1, 0, 1} INSUFFICIENT 2. X < 0 or X > 1 INSUFFICIENT 1,2. The intersection of the sets {-1, 0, 1} and {... 4, 3, 2, -1, -2, -3, ...} is {-1} SUFFICIENT Answer C BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficie...

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x+y = 3*n-14 Putting n = 5, x+y = 1. If any one of x and y is 0, the other is 1, and none of 543012 or 543102 is divisible by 7. Hence try x+y = 4, then 543312 is divisible. Trial and error method, not direct method. Yes it worked out early in this case, but x+y could actually be 1,4,7,10,13,16 bef...

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Well the obvious solution would be to test for divisibility by 7,3,2. Unfortunately, though, the test for 7 is not so straight forward. Is it doable? Yes. But I don't suspect this is a realistic GMAT question. Incidentally, xy = 31. Oh and interestingly, here is the original problem source: http://w...

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oki got it x^4+4 => (x^2)^2 + 2^2 + 2(2)(x^2) - 2(2)(x^2) => (x^2 + 2)^2 - 4x^2 => (x^2 + 2 - 2x)(x^2 + 2 +2x) Not a prime no Nice question.. this was one nasty trap :D Option [spoiler]F- The ques itself is suff :D[/spoiler] Well, not quite. Do you see it? 1. X > -1 Let X=0, then X^4+4 = 4, non-pri...

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rijul007 wrote:

chieftang wrote:If X^4 + 4 prime?

1. 2(X+3) < 3X+7

2. X > 1


Source: Original

IMO E
we dont know whether x is an integer or not

That was not intentional. The original question has now been reworded to indicate X is an integer.

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Greatest Prime Factor

Let P = 200! + 1.

Then, the greatest prime factor of P must be:

(A) Less than 40
(B) Between 40 and 80
(C) Between 80 and 120
(D) Between 120 and 160
(E) Greater than 160


Source: GMAT Hints

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Yep! Indeed my OA for this one is B!

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FYI: http://www.beatthegmat.com/percentages-t98432.html