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
Percent Question
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Let the 1997 rent = 100.kullayappayenugula 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
Saw the solution in OG but looking for better explanation.
Increase in 1998 = (x/100)*100 = x.
Rent in 1998 = 100+x.
Decrease in 1999 = y/100*(100+x) = y + xy/100
Total percent change = increase - decrease = x - (y + xy/100) = x - y - xy/100.
For the rent in 1999 to be higher than the rent in 1997, the total percent change must be POSITIVE.
Question rephrased: Is x - y - xy/100 > 0?
Statement 1: x > y
If x=20 and y=10, then x - y - xy/100 = 20 - 10 - (20*10)/100 = 8.
In this case, the percent change is POSITIVE.
If x=200 and y=100, then x - y - xy/100 = 200 - 100 - (200*100)/100 = -100.
In this case, the percent change is NEGATIVE.
INSUFFICIENT.
Statement 2: x-y > xy/100
Thus, x - y - xy/100 > 0.
SUFFICIENT.
The correct answer is B.
It can be helpful to know the following formulas for repeated percent change:
If a value increases by x% and then by another y%, the total percent change = x + y + xy/100.
If a value increases by x% and then decreases by y%, the total percent change = x - y - xy/100.
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Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
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