Bronson wrote:Is 1/(a-b) < b-a ?
Stat1) a<b
Stat2) 1<!a-b!
(1) if a is less than b, then (a-b) is negative. So, 1/(a-b) is also negative.
Also, if a - b is negative, then b-a is positive.
So, 1/(a-b) is negative and b-a is positive.. therefore, 1/(a-b) is definitely less than b-a. Statement (1) is sufficient.
(2) if 1 is less than the abs val of (a-b), then a-b is greater than 1 or a-b is less than -1. However, this doesn't tell us the relationship between a and b, so statement 2 is insufficient.
For example, we could choose the values:
a=10 b=5, since 1 is less than 5. We then ask the original question:
is 1/(10-5) greater than (5-10)? Or is 1/5 greater than -5. Yes it is!
We could also choose the values a= -10 and b = -5 (since 1 is less than 5). We then ask the original question:
Is 1/(-10 --5) greater than (-5 --10)?
In other words, is 1/-5 greater than +5 ? No, it isn't!
Since we can get both a yes and a no, statement (2) is insufficient.
1 is sufficient, 2 isn't.. choice (A) is correct.
ps: I had to edit this post 8 times to finally get it to format correctly - any time I used a greater than or less than sign it messed everythign up.. very frustrating!