percentage problem

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percentage problem

by princessss » Tue Oct 12, 2010 7:05 am
Angela's grade was in the 90th percentile out of 80 grades in her class. In another class there were 19 grades higher than Angela's. If nobody had Angela's grade, then Angela was what percentile of the two classes combined?

a) 72
b) 80
c) 81
d) 85
e) 92
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by kvcpk » Tue Oct 12, 2010 7:17 am
princessss wrote:Angela's grade was in the 90th percentile out of 80 grades in her class. In another class there were 19 grades higher than Angela's. If nobody had Angela's grade, then Angela was what percentile of the two classes combined?

a) 72
b) 80
c) 81
d) 85
e) 92
Angela's grade was 90th percentile.
which means 90% of the graders were below her.
90% of 80 = 72

Hence 71 were below Angela's grade and 8 were above.

In another calss 60 were below Angela's grade and 19 were above.

Combined:
131 were below and 27 were above.
Total strength= 80 + 80= 160

Hence angela's percentile = 131/160 * 100 = 81....
pick C.

I think I am missing something. Whats OA?
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by Tani » Tue Oct 12, 2010 9:48 am
Where does it say how many are in the other class? If there re 500, the answer would be very different.
Tani Wolff

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by princessss » Tue Oct 12, 2010 11:49 am
It should be 85.
Someone posted here on the forum 198 quantitative questions in a word document and I got this problem there, it is possible that there is a mistake, I found some mistakes already in the document. I was also confused about the other class and the number of students in it. I posted the question because I thought that maybe it doesn't matter somehow but it must be a mistake than..

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by selango » Tue Oct 12, 2010 12:04 pm
I think this question is wrong.

The below question is the original one from GMATPREP.I posted it long back.Check this.

https://www.beatthegmat.com/gmat-prep-prob-t58495.html
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by princessss » Tue Oct 12, 2010 12:13 pm
It's a different thing now.. I looks like that document is full of mistakes :( thank for your help