# MATH 180: Combinatorics

Homeworks:
Due: Wednesday at 12:00P (at beginning of class) (starting October 5)

Homework 1:(due October 5)
Section 5.1, problems 3, 6, 7, 11, 14, 23, 27, 30, 38, 39;
Section 5.2, problems 4, 11, 13, 16c, 16d, 30, 33c, 60a, 67a, 69a;
Bonus problem: section 5.2, problem 77.

Homework 2:(due October 12)
Section 5.3: 8, 18, 24, 26, 32
Section 5.4: 4, 8, 14, 18, 30, 40, 56, 62
Section 5.5: 14b, 14d, 14f, 26, 28, 30, 35b
Bonus problem: is here.
Homework 3:(due October 19)
Note: *-ed problems are for exercise and will not be graded
Section 6.1: 7*, 8(a)(b), 14, 15*, 24
Section 6.2: 6, 7*, 12, 16, 17*, 18, 25*, 37
Section 6.3: 2, 4, 11*, 16, 19a*
Bonus problem: Section 6.3, problem 21
Solutions (password protected) can be found here.
Homework 4,Due Tuesday October 25 in section!!!
Note: *-ed problems are for exercise and will not be graded
Section 6.4: 3*, 6, 7*, 8, 14
Section 7.1: 3*, 6, 8, 17*, 20(a) and (b)
Section 7.3: 3*, 5*, 6, 9
Homework 5, Due Wednesday, November 2:
Note: *-ed problems are for exercise and will not be graded
Section 7.4: 3*, 9*, 6, 10, 16
Section 7.5: 1*, 3*, 8, 14 (Correction: problem 4 removed from hw list.)
Homework 6, due Wednesday, November 9:
Note: *-ed problems are for exercise and will not be graded
Section 8.1: 12, 11*, 15*, 20
Section 8.2: 5*, 8, 12, 27*, 32
Section 1.1: 7*, 4, 6, 17*, 18
Bonus problem: Section 8.2, problem 44b
Homework 7, due Wednesday, November 16:
Note: *-ed problems are for exercise and will not be graded
Section 1.2: 5*b d f g i l, 6 (a)(e)(g),8,11*
Section 1.3: 2, 3*, 4, 7* (Note: the complement of G=(V,E) is \bar{G} =(V,E'), where E'={(a,b)|(a,b) \not\in E}; in other words - it's the graph on the same vertices, where 2 vertices are connected by an edge iff they are not connected in G))
Section 1.4: 2, 3* a f h k l, 5*, 8, 12ab, 14, 16 (use corollary to Euler's formula, page 36)
Bonus problem: Section 1.4, problem 26
Homework 8, due Wednesday, November 23:
Note: *-ed problems are for exercise and will not be graded
Section 2.1:1*,2,3*,8,12(a)(c), 14
Section 2.2:2, 3*, 4(c)(j)(o),7*, 9*, 10, 14, 16, 19*, 21*
Bonus problem: 24 (do part (b) for all n, not just e.g. n=3)
Homework 9, due Wednesday, November 30:
Note: *-ed problems are for exercise and will not be graded
Section 2.3:1(a)(c)(f), 1*(o), 9, 10, 13*
Section 2.4:1*, 2, 3*, 4, 11*, 13*, 14, 16
Bonus problem: section 2.3, 16