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- #1

- Apr 13, 2013

- 3,720

I used the formula [tex] x_{1}+x_{2}+x_{3}+x_{4}+x_{5}=8 [/tex] ,where [tex]x_{1}=0 [/tex].So,it is [tex] \binom{n+k-1}{k}=\binom{4+8-1}{8}=\binom{11}{8}=495 [/tex] ,right?Or do I have to replace n with 5?Because,the formula is satisfied for [tex] x_{i} \geq 0 [/tex] ..