Hi fambrini,

This question was discussed here:

https://www.beatthegmat.com/og-13-127-t288372.html

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Rich

fambrini wrote:The annual rent collected by a corporation from a certain building was x percent more in 1998 than in 1997 and y percent less in 1999 than in 1998. Was the annual rent collected by the corporation from the building more in 1999 than in 1997?

1) x > y

2) xy / 100 > x - y

OA: B

Say the rent in 1997 = $100.

=> Rent in 1998 = $100 + x

=> Rent in 1999 = $(100+x)(1-y%)

We have to decide: 100 < = > (100+x)(1-y%)

=> 100 < = > 100 - xy% + x -100y%

=> 0 < = > x - y - xy/100

=> xy/100 < = > x - y.

From S2, we know that xy/100 > x - y. Sufficient.

Let us analyze S1.

xy/100 < = > x - y can be written as y > = < x( 1-y%).

We see that if we increase the value of y, thought the value of LHS increase, due to the presence of the factor (1-y%) in RHS, the value of RHS also increases. The opposite goes if we decrease the value of y. So we cannot bank on the information in S1: x > y. Insufficient!

Hope this helps!

-Jay
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