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The annual rent collected by a corporation from a certain
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01 Oct 2008, 11:03
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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 == Message from GMAT Club Team == This is not a quality discussion. It has been retired. If you would like to discuss this question please repost it in the respective forum. Thank you! To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative  Verbal Please note  we may remove posts that do not follow our posting guidelines. Thank you.



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Re: DS: Annual Rent
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01 Oct 2008, 11:32
1) Insufficient
Substitute 20 for x, 19 for y, and 100 for rent in 1997. 1997: 100 1998: 100+100*0.2 = 120 1999: 120120*0.19 = 12022.8 = 97.2 which gives an answer "NO' that 1999 rent > 1997 rent
Substitute 20 for x, 1 for y, and 100 for rent in 1997 1997: 100 1998: 100+100*0.2 = 120 1999: 120120*0.01 = 1201.2 = 118.8 which gives an answer "YES" that 1999 rent > 1997 rent
2) Insufficient
Substitute 20 for x, 19 for y, and 100 for rent in 1997 20*19/100 < 2019 380/100 < 1 3.8 < 1 Not true for this condition
Substitiute 20 for x, 1 for y, and 100 for rent in 1997 20*1/100 < 201 1/5 < 19 True for this condition
When combining both conditions x>y and xy/100 < xy, we plug in the number 20 for x, 1 for y, and 100 for rent because these numbers satisfies both conditions as shown above. When x = 20, y = 1, x>y. When x = 20, y = 1, xy/100 < xy 20*1/100 < 201 20/100 < 19 1/5 < 19
Therefore, the answer is C.



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Re: DS: Annual Rent
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Updated on: 01 Oct 2008, 12:32
vksunder 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 Answer is B. Let rent in 1997 = 1 rent in 1998 = 1+(x/100) rent in 1999 = [1+(x/100)]+[{1+(x/100)}{1(y/100)}].......coz [a + b% of a] = [1+(x/100)] [1(y/100)] The question demands: Is [1+(x/100)] [1(y/100)] > 1 ?? assume this to be true & solve it further: => (100+x)(100y)> 10000 => 10000 + 100x 100y xy >10000 => 100x100yxy>0 => 100(xy)>xy => xy > (xy/100) This is exactly given by option 2. Therefore, option 2 is sufficient. x>y i.e. option1 doesnt lead us anywhere. Therefore answer is B.
Originally posted by jatinrai on 01 Oct 2008, 11:39.
Last edited by jatinrai on 01 Oct 2008, 12:32, edited 1 time in total.



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Re: DS: Annual Rent
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01 Oct 2008, 12:15
jatinrai wrote: vksunder 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 Answer is B. Let rent in 1997 = 1 rent in 1998 = 1+(x/100) rent in 1999 = [1+(x/100)]+[{1+(x/100)}{1+(y/100)}].......coz [a + b% of a] = [1+(x/100)] [1+(y/100)]The question demands: Is [1+(x/100)] [1+(y/100)] > 1 ?? assume this to be true & solve it further: => (100+x)(100y)> 10000 => 10000 + 100x 100y xy >10000 => 100x100yxy>0 => 100(xy)>xy => xy > (xy/100) This is exactly given by option 2. Therefore, option 2 is sufficient. x>y i.e. option1 doesnt lead us anywhere. Therefore answer is B. I think you meant 1(y/100) here.



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Re: DS: Annual Rent
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01 Oct 2008, 12:32
scthakur wrote: jatinrai wrote: vksunder 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 Answer is B. Let rent in 1997 = 1 rent in 1998 = 1+(x/100) rent in 1999 = [1+(x/100)]+[{1+(x/100)}{1+(y/100)}].......coz [a + b% of a] = [1+(x/100)] [1+(y/100)]The question demands: Is [1+(x/100)] [1+(y/100)] > 1 ?? assume this to be true & solve it further: => (100+x)(100y)> 10000 => 10000 + 100x 100y xy >10000 => 100x100yxy>0 => 100(xy)>xy => xy > (xy/100) This is exactly given by option 2. Therefore, option 2 is sufficient. x>y i.e. option1 doesnt lead us anywhere. Therefore answer is B. I think you meant 1(y/100) here. Yup. Solved it on paper then copied. Hence, error.



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Re: DS: Annual Rent
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01 Oct 2008, 20:16
Can v hv sum short cut method for this question?



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Re: DS: Annual Rent
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01 Oct 2008, 20:37
As far as I can understand [1+(x/100)] [1(y/100)] is diference b/w rent in 1999 and 1998. Y did u consider it >1 ? jatinrai wrote: vksunder 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 Answer is B. Let rent in 1997 = 1 rent in 1998 = 1+(x/100) rent in 1999 = [1+(x/100)]+[{1+(x/100)}{1(y/100)}].......coz [a + b% of a] = [1+(x/100)] [1(y/100)] The question demands: Is [1+(x/100)] [1(y/100)] > 1 ??assume this to be true & solve it further: => (100+x)(100y)> 10000 => 10000 + 100x 100y xy >10000 => 100x100yxy>0 => 100(xy)>xy => xy > (xy/100) This is exactly given by option 2. Therefore, option 2 is sufficient. x>y i.e. option1 doesnt lead us anywhere. Therefore answer is B.



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Re: DS: Annual Rent
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01 Oct 2008, 21:28
x percent more, y percent less
So can we assume x, y >0??
If x,y > 0 then (2) <=> x  y>0 <=> (1)
annual rent in 1997 & 1999 are connected by rent in 1998, so (1) is sufficient hence (2) is sufficient
My answer is D



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Re: DS: Annual Rent
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01 Oct 2008, 21:50
vksunder 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 B % increase from 1997 to 1999 P = (1+x/100)(1y/100) = 1+ x/100y/100 xy/(100*100) = 1+ 1/100 ( xyxy/100) from equ 2 xy/100 < x – y > xyxy/100>0 so P>1
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Re: DS: Annual Rent
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01 Oct 2008, 21:53
lylya4 wrote: x percent more, y percent less
So can we assume x, y >0??
If x,y > 0 then (2) <=> x  y>0 <=> (1)
annual rent in 1997 & 1999 are connected by rent in 1998, so (1) is sufficient hence (2) is sufficient
My answer is D I don't think you can assume that y>0 since you are told that y is less then 0 (negative).



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Re: DS: Annual Rent
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01 Oct 2008, 21:53
lylya4 wrote: x percent more, y percent less
So can we assume x, y >0??
If x,y > 0 then (2) x  y>0 (1)
annual rent in 1997 & 1999 are connected by rent in 1998, so (1) is sufficient hence (2) is sufficient
My answer is D (1) is not suffcient for e.g same intial ren 100. increased by 20.01% then rent would be ~120 decreased by 20% 12024= 96 for e.g same intial ren 100. increased by 40% then rent would be ~140 decreased by 20% 14028=116 == Message from GMAT Club Team == This is not a quality discussion. It has been retired. If you would like to discuss this question please repost it in the respective forum. Thank you! To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative  Verbal Please note  we may remove posts that do not follow our posting guidelines. Thank you.
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Re: DS: Annual Rent &nbs
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