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Online Probability Class Week 3 - Combos

 
 
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Online Probability Class Week 3 - Combos
by Winny ZHAO - Thursday, 18 July 2019, 12:38 PM
 

The question states that there are 5 pennies and two match sticks and it asks to find the number of ways that you can put them in a row, essentially making it a stars and bars problem. The answer was 7 choose 2 and was found by 5+3-1 choose 3-1. I don't get why a three is on the top and bottom when the question says two. Also something is the -1 on the bottom which I don't understand why is there.

 
Picture of Eva Gong
Re: Online Probability Class Week 3 - Combos
by Eva Gong - Saturday, 31 August 2019, 5:21 PM
 

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