Question

minimum number of combination-pairs, without replacement, to ensure a value appears

score 291 · Answer 1 · 2026-03-25 14:22:37

291

Views

minimum number of combination-pairs, without replacement, to ensure a value appears

Published on 25 Mar 2026 - 14:22

score 2k · Answer 2 · 2026-03-24 22:01:43

2k

Views

How many lattice paths are there from $(0,0)$ to $(2n,2n)$ that avoids odd points

Published on 24 Mar 2026 - 22:01

score 142 · Answer 3 · 2026-04-01 00:42:52

142

Views

Cardinality of a quotient

Published on 01 Apr 2026 - 0:42

score 389 · Answer 4 · 2026-03-25 06:21:00

389

Views

Evaluate $\sum_{k=1}^n\frac{1}{k}\binom{n}{k}$

Published on 25 Mar 2026 - 6:21

score 163 · Answer 5 · 2018-02-11 05:58:18

163

Views

Jess invited all 8 of her friends to a party, but only 5 people showed up.

Published on 11 Feb 2018 - 5:58

score 139 · Answer 6 · 2026-03-25 23:35:04

139

Views

Infinite Sum with Combinatoric Expression

Published on 25 Mar 2026 - 23:35

score 37 · Answer 7 · 2026-03-22 04:53:09

37

Views

Is there a similar notion of cycle type commonly in use for finite partitions, where instead of cycle sizes one counts the block sizes?

Published on 22 Mar 2026 - 4:53

score 82 · Answer 8 · 2018-02-11 08:50:56

82

Views

$\sum_{k=n}^{2n} \binom{k}{n} 2^{-k}$

Published on 11 Feb 2018 - 8:50

score 98 · Answer 9 · 2026-03-25 07:45:57

98

Views

Prove that: $\frac{(n+0)!}{0!}+\frac{(n+1)!}{1!}+...+\frac{(n+n)!}{n!}=\frac{(2n+1)!}{(n+1)!}$

Published on 25 Mar 2026 - 7:45

score 60 · Answer 10 · 2026-03-24 23:46:13

60

Views

Upper bound on choosing at least $k$ items out of $n$

Published on 24 Mar 2026 - 23:46

score 298 · Answer 11 · 2026-03-24 17:51:55

298

Views

Convex combination of $2^n$ vectors from cartesian products of half-spaces

Published on 24 Mar 2026 - 17:51

score 182 · Answer 12 · 2018-02-11 13:07:36

182

Views

Number of monotonic sequence on $\{1,2,3,4\}$

Published on 11 Feb 2018 - 13:07

score 122 · Answer 13 · 2026-03-26 20:37:46

122

Views

Simple solution to coloured marble problem seems off?

Published on 26 Mar 2026 - 20:37

score 1.1k · Answer 14 · 2026-03-26 22:29:40

1.1k

Views

How many different $3$-digit numbers can be formed if the digits $1$, $2$, $2$, $3$, $4$ are placed on separate cards?

Published on 26 Mar 2026 - 22:29

score 81 · Answer 15 · 2018-02-11 18:25:05

81

Views

How many ways can I choose a subset such that it contains at least one yellow and one blue marble?

Published on 11 Feb 2018 - 18:25

List Question

minimum number of combination-pairs, without replacement, to ensure a value appears

How many lattice paths are there from $(0,0)$ to $(2n,2n)$ that avoids odd points

Cardinality of a quotient

Evaluate $\sum_{k=1}^n\frac{1}{k}\binom{n}{k}$

Jess invited all 8 of her friends to a party, but only 5 people showed up.

Infinite Sum with Combinatoric Expression

Is there a similar notion of cycle type commonly in use for finite partitions, where instead of cycle sizes one counts the block sizes?

$\sum_{k=n}^{2n} \binom{k}{n} 2^{-k}$

Prove that: $\frac{(n+0)!}{0!}+\frac{(n+1)!}{1!}+...+\frac{(n+n)!}{n!}=\frac{(2n+1)!}{(n+1)!}$

Upper bound on choosing at least $k$ items out of $n$

Convex combination of $2^n$ vectors from cartesian products of half-spaces

Number of monotonic sequence on $\{1,2,3,4\}$

Simple solution to coloured marble problem seems off?

How many different $3$-digit numbers can be formed if the digits $1$, $2$, $2$, $3$, $4$ are placed on separate cards?

How many ways can I choose a subset such that it contains at least one yellow and one blue marble?

Trending Questions

Popular # Hahtags

Popular Questions