Advanced GMAT quant guide Pg 101 - Try it problem 4-4

[jp.jprasanna]

Hi -In the advanced GMAT Quant guide page 101 try it problem 4-4

If the 3 digit integer x ="abc", where a,b, and c represent nonzero digit of x, what is the value of x ?

1/ a >= 3b
2/ b >= 3c

I understand the solution given (Ans is C, using both and the value is 931) but my question is do we have anything that restrains the value of x to be positive

For example if i take c = -1, then x = -931 which is different value!
The set of Integers can be anything correct? { leaving 0 as per the constrain in the question then we can have - ±1, ±2, ±3, ..... }

Cheers

[tim]

yeah, anytime you are given a 3-digit integer ABC, it is assumed that A, B, and C are all pulled from the set {0,1,2,3,4,5,6,7,8,9} (keeping in mind A cannot be 0 since then it would just be a 2-digit number). this forces x to be positive..