Brent@GMATPrepNow wrote:
If x > 0, b > a, and 2x + 5 < 3x + 1, then which of the following COULD be a value of x?
i) 4.39
ii) 7.17
iii) 9.27
A) i and ii only
B) ii and iii only
C) i and iii only
D) iii only
E) i, ii and iii
Here's a useful triangle property:
So, if b > a, then we know that 3x + 1 < 4x - 8
We're also told that 2x + 5 < 3x + 1
So, we can create the following 3-part inequality: 2x + 5 < 3x + 1 < 4x - 8
Subtract 2x from all 3 sides: 5 < x + 1 < 2x - 8
When we examine 5 < x + 1, we can conclude that 4 < x. So, x is greater than 4
When we examine x + 1 < 2x - 8, we can conclude that 9 < x. So, x is greater than 9
So, we know that x is greater than 4 AND x is greater than 9
So, it MUST be the case that
x is greater than 9
Check the statements.....
Only statement iii works.
Answer: D
Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
