Question

Find all such mappings where $A=\{1,2,3,4\}$, $B=\{1,2,3,4,5,6\}$ and $f:A \to B$ is an injective mapping such that $f(i) \neq i ~\forall i=1,2,3,4$.

score 674 · Answer 1 · 2026-04-15 15:46:09

Find all such mappings where $A=\{1,2,3,4\}$, $B=\{1,2,3,4,5,6\}$ and $f:A \to B$ is an injective mapping such that $f(i) \neq i ~\forall i=1,2,3,4$.

score 40 · Answer 2 · 2026-04-12 08:29:56

40

Views

Probability of taking seats

Published on 12 Apr 2026 - 8:29

score 59 · Answer 3 · 2026-04-13 04:06:24

59

Views

Expected value of winning the lottery

Published on 13 Apr 2026 - 4:06

score 71 · Answer 4 · 2026-04-15 15:24:40

71

Views

How many numbers can be formed?

Published on 15 Apr 2026 - 15:24

score 67 · Answer 5 · 2026-04-16 06:42:02

67

Views

Mean number of edges in a hypercube graph in which random nodes are deleted

Published on 16 Apr 2026 - 6:42

score 61 · Answer 6 · 2026-04-16 17:04:29

61

Views

$N_k$ is the number of pairs $(a,b)$ of non-negative integers such that $ka+(k+1)b=n+1-k$. Find $N_1+N_2+\cdots N_{n+1}$.

Published on 16 Apr 2026 - 17:04

score 147 · Answer 7 · 2026-04-14 05:03:39

147

Views

Counting non-nesting multi-permutations

Published on 14 Apr 2026 - 5:03

score 2.9k · Answer 8 · 2026-04-14 16:41:26

2.9k

Views

How many triangles are there in the 'picture' of $K_5$? Different ways to count it

Published on 14 Apr 2026 - 16:41

score 301 · Answer 9 · 2026-04-12 02:37:19

301

Views

Distribution of random subintervals lengths

Published on 12 Apr 2026 - 2:37

score 85 · Answer 10 · 2026-04-21 06:34:44

85

Views

Deviating from the mean +-1 variables

Published on 21 Apr 2026 - 6:34

score 505 · Answer 11 · 2026-04-14 15:15:56

505

Views

Drawing at least that many "distinct" balls of each color

Published on 14 Apr 2026 - 15:15

score 100 · Answer 12 · 2026-04-15 10:37:37

100

Views

How many arrangements of k items from n items when there are duplicate items

Published on 15 Apr 2026 - 10:37

score 168 · Answer 13 · 2026-04-18 08:44:27

168

Views

positivity in bases of symmetric functions

Published on 18 Apr 2026 - 8:44

score 122 · Answer 14 · 2026-04-20 13:25:36

122

Views

closed-form expression for expected value, $E\left\{X_1\cdots X_k\right\}$ for multinomial distribution

Published on 20 Apr 2026 - 13:25

score 299 · Answer 15 · 2026-04-10 18:20:05

299

Views

Find a closed formula for $ \sum _{k=0}^n k^2 5^k $

Published on 10 Apr 2026 - 18:20

List Question

Find all such mappings where $A=\{1,2,3,4\}$, $B=\{1,2,3,4,5,6\}$ and $f:A \to B$ is an injective mapping such that $f(i) \neq i ~\forall i=1,2,3,4$.

Probability of taking seats

Expected value of winning the lottery

How many numbers can be formed?

Mean number of edges in a hypercube graph in which random nodes are deleted

$N_k$ is the number of pairs $(a,b)$ of non-negative integers such that $ka+(k+1)b=n+1-k$. Find $N_1+N_2+\cdots N_{n+1}$.

Counting non-nesting multi-permutations

How many triangles are there in the 'picture' of $K_5$? Different ways to count it

Distribution of random subintervals lengths

Deviating from the mean +-1 variables

Drawing at least that many "distinct" balls of each color

How many arrangements of k items from n items when there are duplicate items

positivity in bases of symmetric functions

closed-form expression for expected value, $E\left\{X_1\cdots X_k\right\}$ for multinomial distribution

Find a closed formula for $ \sum _{k=0}^n k^2 5^k $

Trending Questions

Popular # Hahtags

Popular Questions