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help w./this problem

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help w./this problem

by mvshah0101 » Wed Sep 06, 2006 5:12 pm
I was wondering if someone could help me with this problem:

We have a bag filled with colored balls: 30 are red, 65 are blue, 110 are green, 50 are yellow, and 89 are black. If we randomly choose balls from the bag, how many must we remove to insure that we remove 70 of the same color?

A. 71

B. 110

C. 141

D. 192

E. 284
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answer

by nbeltraniii » Wed Sep 06, 2006 7:16 pm
since the problem is to ensure removal of 70 of the same color, in a bag where

30 are red
65 are blue
110 are green
50 yellow
89 black


considering only the most extreme case, (i.e. maximum number of random removal to ensure 70 of the same color), picking 70 of the same color is ensured only when green or black are picked,

hence, all reds must be picked first, and all blue, and all yellow, plus at least 69 of either green (or black), and plus 70 of black (or green -- depending on which was picked 69 times)...

thus there is a need to randomly remove 30+65+50+69+70=284

hope that helps.

thanks,

nick
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by aim-wsc » Thu Sep 07, 2006 4:53 am
nice one, n belt rani!
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by imvindicated » Sun Jun 27, 2010 12:01 am
Hi, I dont quite understand the reasoning behind the answer. Infact, I cant seem to understand what exactly the question asks for.

Could someone help me out ? Thanks a lot.
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