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How many ways are there to put 5 balls in 3 boxes if the balls are not distinguishable but the boxes are?

 

That is the question but I have been trying it and getting many different answers, can someone help?

Mr.Owl  Oct 23, 2017
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2+0 Answers

 #1
avatar+78762 
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As Melody says.....take my answers at your own peril, Mr. Owl

 

If we have no restictions,  the number of ways is given by

C ( k + n - 1, n - 1)      here k is the number of balls and n is the number of boxes

C ( 5 + 3 - 1 , 3 - 1)

C ( 7, 2)  = 21 ways

 

If we have to have at least one ball in each box

C ( k - 1, n - 1)

C ( 5 - 1 , 3 - 1 )

C ( 4, 2)   =  6 ways

 

BTW ......here's a website that will help you with these type of problems :

 

http://www.careerbless.com/aptitude/qa/permutations_combinations_imp7.php

 

 

cool cool cool

CPhill  Oct 23, 2017
 #2
avatar+304 
+2

Thanks a million!

Mr.Owl  Oct 23, 2017

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