GMAT - QUANT QUESTIONS AND ANSWERS

4^x + 4^-x = 2 - Answer-To get reciprocals to equal 2, both must be 1, so x = 0 Point Q lies in the interior of a particular circle. Is point Q the center of the circle? (1) There exist points A, B, and C, all distinct points on the circle's circumference, such that the distances QA, QB, and QC are identical. - Answer-Yes Point Q lies in the interior of a particular circle. Is point Q the center of the circle? (2) At least two different diameters of the circle contain point Q. - Answer-Yes, All diameters of a circle intersect at the circle's center and nowhere else. Therefore, if Q is the point of intersection of two or more of the circle's diameters, then Q must be the center of the circle. The statement is sufficient. If x is a prime number, what is the value of x? (2) The average of any x consecutive integers is an integer. - Answer-X must be odd Then there are an odd number of members in a consecutive set, the mean/median will be a member of the set and thus an integer (e.g. 5,6,7,8,9; mean/median = 7). In contrast when there are an even number of members in the set, the mean/median will NOT be a member of the set and thus NOT an integer (e.g. 5,6,7,8; mean/median = 6.5). 1 / (a+b) 1/a + 1/b - Answer-If a and b are positive, then true Need to test a or b as 1 as well as 0(a or b - decimal) 1 If negative, then generally won't be true