is 1/a-b < b-a?
(1) a < b
(2) 1 < |a-b|
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- ashish.jere
- Students
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- mangipudi
- Course Students
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Re: inequality
(1) a < b
=> a-b < 0 and b-a > 0
=> 1/(a-b) < 0 and b-a > 0
=> 1/(a-b) < b-a
sufficient
2. From this you dont which of a and b is greater .
All you know is that the distance between them is greater than 1.
Insufficient.
=> a-b < 0 and b-a > 0
=> 1/(a-b) < 0 and b-a > 0
=> 1/(a-b) < b-a
sufficient
2. From this you dont which of a and b is greater .
All you know is that the distance between them is greater than 1.
Insufficient.
- Ben Ku
- ManhattanGMAT Staff
- Posts: 817
- Joined: Sat Nov 03, 2007 7:49 pm
Re: inequality
I agree with mangipudi's solution.
Statement (1) helps us know that a - b is negative, while b - a is positive. So
Is 1 / (a-b) < b - a?
Is (Negative) < (Positive)?
The answer is Yes, so (1) is sufficient.
Statement (2) is not sufficient because we still don't know how a - b compares with b - a.
The answer is (A). Hope that helps!
Statement (1) helps us know that a - b is negative, while b - a is positive. So
Is 1 / (a-b) < b - a?
Is (Negative) < (Positive)?
The answer is Yes, so (1) is sufficient.
Statement (2) is not sufficient because we still don't know how a - b compares with b - a.
The answer is (A). Hope that helps!
Ben Ku
Instructor
ManhattanGMAT
Instructor
ManhattanGMAT
3 posts Page 1 of 1