How many possible sudoku puzzles are there? In the lottery what is the chance that two winning balls have consecutive numbers? Who invented Pascal's triangle? (it was not Pascal) Combinatorics the branch of mathematics concerned with selecting arranging & listing or counting collections of objects works to answer all these questions Dating back some 3000 years & initially consisting mainly of the study of permutations & combinations its scope has broadened to include topics such as graph theory partitions of numbers block designs design of codes & latin squares In this Very Short Introduction Robin Wilson gives an overview of the field & its applications in mathematics & computer theory considering problems from the shortest routes covering certain stops to the minimum number of colours needed to colour a map with different colours for neighbouring countries ABOUT THE SERIES The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost every subject area These pocket-sized books are the perfect way to get ahead in a new subject quickly Our expert authors combine facts analysis perspective new ideas & enthusiasm to make interesting & challenging topics highly readable