# Unit information: Combinatorics in 2021/22

Unit name Combinatorics MATH20002 20 I/5 Teaching Block 1 (weeks 1 - 12) Dr. Harris Not open MATH10010 Introduction to Proofs and Group Theory, MATH10011 Analysis, MATH10013 Probability and Statistics and MATH10015 Linear Algebra None School of Mathematics Faculty of Science

## Description including Unit Aims

Unit Aims

This unit serves as an introduction to combinatorics, developing fundamental aspects of a diverse range of topics in discrete mathematics such as enumeration, extremal graph theory, Ramsey theory and random walks. The unit aims to develop and improve students’ problem-solving and theorem-proving skills, building on those acquired in first-year courses. Moreover, it seeks to enhance students’ appreciation of the interconnectedness of different areas of mathematics by introducing probabilistic, analytic and algebraic techniques.

Unit Description

Combinatorics is the study of discrete structures, which are ubiquitous in our everyday lives. While combinatorics has important practical applications (for example to networking, optimisation, and statistical physics), problems of a combinatorial nature also arise in many areas of pure mathematics such as algebra, probability, topology and geometry.

The course will start with a revision of various enumeration techniques. The unit will then proceed to introduce the basic notions and fundamental results of graph theory, including Turán’s theorem on independent sets, Hall’s marriage theorem, Euler’s formula for planar graphs and Kuratowski’s theorem. In the last part of the unit probabilistic and algebraic methods will be used to study more advanced topics in graph theory, including Ramsey’s theorem and random walks.

## Intended Learning Outcomes

Students who successfully complete the unit should:  be proficient at enumeration, rearrangements of finite sets;  be familiar with the basic definitions and concepts in graph theory, including trees, cycles, connectivity, matchings, planarity;  understand, be able to prove and apply the fundamental results derived in the course, and solve unseen problems of a similar kind;  understand and be able to apply methods from elementary probability, analysis and linear algebra to a range of problems in discrete mathematics, including Ramsey theory, isoperimetry and random walks.

In addition, students should have  learnt how to give a mathematical formulation to word problems of a discrete nature;  improved their problem-solving and theorem-proving skills;  gained an appreciation of how methods from probability, analysis and algebra can be used to solve problems in discrete mathematics.

## Teaching Information

The unit will be taught through a combination of

• synchronous online and, if subsequently possible, face-to-face lectures
• asynchronous online materials, including narrated presentations and worked examples
• guided asynchronous independent activities such as problem sheets and/or other exercises
• synchronous weekly group problem/example classes, workshops and/or tutorials
• synchronous weekly group tutorials
• synchronous weekly office hours

## Assessment Information

• 90% Timed, open-book examination
• 10% Coursework

Raw scores on the examinations will be determined according to the marking scheme written on the examination paper. The marking scheme, indicating the maximum score per question, is a guide to the relative weighting of the questions. Raw scores are moderated as described in the Undergraduate Handbook.

If you fail this unit and are required to resit, reassessment is by a written examination in the August/September Resit and Supplementary exam period.

## Resources

If this unit has a Resource List, you will normally find a link to it in the Blackboard area for the unit. Sometimes there will be a separate link for each weekly topic.

If you are unable to access a list through Blackboard, you can also find it via the Resource Lists homepage. Search for the list by the unit name or code (e.g. MATH20002).

How much time the unit requires
Each credit equates to 10 hours of total student input. For example a 20 credit unit will take you 200 hours of study to complete. Your total learning time is made up of contact time, directed learning tasks, independent learning and assessment activity.