How to prove something combinatorially
116356
Combinatorial proof of $2 \cdot 3^0 + 2 \cdot 3^1 + 2 \cdot 3^2 + \cdots 2 \cdot 3^{n-1} = 3^n-1$
74523
Proof by Cases involving divisibility
141496
Could someone make the proof into a hinted exercise?
156383
Proving a combinatorial identity without double counting
29828
Combinatorial proof of $\sum^{n}_{i=1}\binom{n}{i}i=n2^{n-1}$.
120074
Prove by Combinatorial Argument that $\binom{n}{k}= \frac{n}{k} \binom{n-1}{k-1}$
82872
Combinatorial proof involving partitions and generating functions
151038
How to prove (A v B), (A → C), (B → D) therefore (C v D)
90904
Combinatorial proof of an identity with squared binomial coefficients
9522
Proving $k \binom{n}{k} = n \binom{n-1}{k-1}$
151935
Proving the predicate $\forall n \in \mathbb{N} , n \geq 2$ using the Pigeonhole principle
74730
Combinatorial Proof of ${{n}\choose{k}} {{k}\choose{j}} = {{n}\choose{j}} {{n-j}\choose{k-j}}$
134440
An unexpected application of non-trivial combinatorics
39872
Good Book On Combinatorics
125263
How to crack the proof
134599
How do I do Combinatorics / Counting?
59831
How to relate combinatorial proof to bipartite graphs?