Prove combinatorial Identity using a combinatorial argument.
158508
Combinatorial Proof for Binomial Identity: $\sum_{k = 0}^n \binom{k}{p} = \binom{n+1}{p+1}$
122006
Proving combinatorial identity $\sum_{k=0}^{n}(-1)^k \binom{2n-k}k 2^{2n-2k} = 2n+1$ "directly"
67927
Combinatorial argument for the identity $k\binom{n}{k} = n\binom{n-1}{k-1}$
14986
Proving a combinatorics equality: $\binom{r}{r} + \binom{r+1}{r} + \cdots + \binom{n}{r} = \binom{n+1}{r+1}$
76368
Proving the Binomial theorem
36388
How to derive this Combinatorial identity
24212
proving how many permutations exist.
39724
Combinatorial Identities
107335
Prove equality between binomial coefficients.
145524
Proving this identity $\sum_k\frac{1}{k}\binom{2k-2}{k-1}\binom{2n-2k+1}{n-k}=\binom{2n}{n-1}$ using lattice paths
149686
Combinatorics and trigonometry identity
114277
Proving in Discrete Structures Problem that $2^N = \binom{N}{0} + \binom{N}{1} + \binom{N}{2} + \dots + \binom{N}{N}$
45204
Combinatorial proofs: having a difficult time understanding how to write them out
116461
Prove the identity $\sum_{k=0}^{n}(-1)^{k}\binom{n}{k}=0$ using a combinatorial interpretation of the positive and negative terms
1139
Combinatorial proof of $\sum_{j=0}^{k} \binom{n}{j} = \sum_{j=0}^k \binom{n-1-j}{k-j}2^j$
34299
Combinatorial proof of $\sum_{k=0}^n k \cdot k! = (n+1)! -1$
103347
combinatorial proof of summation