who can play the harp

Problem Solving — algebra and arithmetic (GMAT Focus Edition)
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who can play the harp

by sanju09 » Fri Jan 28, 2011 6:18 am
At School X, there are 50 students who can play the harp and 60 students who can play the cello. If there are 15 students who can play both the harp and the cello, how many students can play either the harp or the cello?
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by towerSpider » Sat Jan 29, 2011 10:04 am
Total: 50 + 60 - 15 ( -15 because these are counted twice) = 95

95 - 15 = 80 = Ans.
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by Tani » Sat Jan 29, 2011 1:52 pm
The formula is:

G1 + G2 - B + N = T

The number in group 1 plus the number in group 2 minus those in both groups plus those in neither group equals the total.
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by VivianKerr » Fri Feb 04, 2011 11:51 am
I can play the harp! Just kidding. :)

Here's my VENN diagram:

Image

We can see that 35 only play the harp (50-15), and 45 only play the cello (60-15).

35 + 45 = 80
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by Tani » Sat Feb 05, 2011 2:45 pm
Funny - I actually can play the cello :-)
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