Lights at Hotel California

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Lights at Hotel California

by sam2304 » Sat Jan 07, 2012 6:05 pm
Eighty percent of the lights at Hotel California are on at 8 p.m. a certain evening. However, forty percent of
the lights that are supposed to be off are actually on and ten percent of the lights that are supposed to be on
are actually off. What percent of the lights that are on are supposed to be off?
A.22(2/9)%
B.16(2/3)%
C.11(1/9)%
D.10%
E.5%
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by GMATGuruNY » Sun Jan 08, 2012 4:17 am
For the weighted average approach, check the link offered by chieftang:

https://www.beatthegmat.com/percentages-t98432.html

An alternate approach is to plug in the answer choices. Check here:

https://www.beatthegmat.com/mgmat-t82447.html
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by ronnie1985 » Mon Jan 09, 2012 3:21 am
QED
(D) 10% is answer.
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