### Questions (14)

 4 How many ways can we distribute $r$ identical balls into $n$ distinct boxes with exactly $m$ boxes empty 3 Find the determinant of $N \times N$ matrix 2 Draw a planar graph with two vertices of degree 3 and four vertices of degree 5, if possible. 2 Evaluate $\sum\limits_{k = 0}^n \binom{n}{n-k} \binom{m}{k}$. Give combinatorical arguments. 1 Solve the recurrence relation $f(n) = 4f(n/3)+5$ where $n=3^k, k=1,2,3…$ and $f(1)=5$

### Reputation (101)

This user has no recent positive reputation changes

### Answers (0)

This user has not answered any questions

### Tags (11)

 0 combinatorics × 12 0 linear-algebra 0 discrete-mathematics × 7 0 matrices 0 generating-functions × 3 0 sequences-and-series 0 recurrence-relations × 3 0 summation 0 graph-theory × 2 0 determinant

### Account (1)

 Mathematics 101 rep 6

### Badges (6)

 Curious Supporter Commentator Scholar Editor Student

### Active bounties (0)

This user has no active bounties

### Votes cast (26)

all time   by type
26 up 9 question
0 down 17 answer