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math challenge I-C hw

 
 
ZhangYizhou的头像
math challenge I-C hw
ZhangYizhou - 2020年04月22日 Wednesday 19:56
 

for chapter stars and bars number 14, I am confused about which one to choose, none of them look right to me.

 
ProfessorAreteem的头像
Re: math challenge I-C hw
ProfessorAreteem - 2020年04月23日 Thursday 10:44
 

Think of this equivalent version of the problem: You have 6 boxes numbered $1$ through $6$, you have $2$ balls inside of the box numbered 1, $3$ balls inside of the box numbered $4$, and $1$ ball inside the box numbered $5$.

If you have the boxes lined up next to each other (in order), you can think of the bars as the sides of the boxes that touch, for example, if you wanted $3$ balls inside box $2$, $4$ balls inside box $5$ and $1$ ball inside box $6$, the arrangement of stars and  bars would look like: $$| ***|||****|*$$