jjjinapinch wrote:If x is a positive integer greater than 1, what is the value of x?
(1) 2x is a common factor of 18 and 24
(2) x is a factor of 6
Official Guide question
Answer: A
Target question: What is the value of x?
Given: x is a positive integer greater than 1
Statement 1: 2x is a common factor of 18 and 24
Positive factors of 18: 1, 2, 3, 6, 9, 18
Positive factors of 24: 1, 2, 3, 4, 6, 8, 12, 24
COMMON factors of 18 and 24: 1, 2, 3, 6
So, 2x = 1, 2x = 2, 2x = 3 or 2x = 6
This means, x = 0.5, x = 1, x = 1.5 or x = 3
Since we're told that x is a positive integer greater than 1, we can see that
x MUST equal 3
Since we can answer the
target question with certainty, statement 1 is SUFFICIENT
Statement 2: x is a factor of 6
So, x could equal 1, 2, 3, or 6
Since we're told that x is a positive integer greater than 1, we can see that
x COULD equal 2, 3, or 6
Since we cannot answer the
target question with certainty, statement 2 is NOT SUFFICIENT
Answer =
A
Cheers,
Brent
