Skip main navigation

New offer! Get 30% off one whole year of Unlimited learning. Subscribe for just £249.99 £174.99. New subscribers only. T&Cs apply

Find out more

Let’s count – The basic principles of combinatorics, 1

Let's count - The basic principles of combinatorics, 1
Do your best in trying to solve the following problems. It is normal that this step will take some time, we recommend to perseverate and wait before looking at the complete solution of the exercises in the video or in the pdf below.

Exercise 1.

How many four letter words can be formed with an alphabet of 26 letters? How many of these are without a repeated letter?

Exercise 2.

How many three letter words without repetition of letters can be made by using the letters (a,b,c,d,e,f) in such a way that either the letter (e) or the letter (f) or both appear?

© CM
This article is from the free online

Combinatorics: Strategies and Methods for Counting

Created by
FutureLearn - Learning For Life

Reach your personal and professional goals

Unlock access to hundreds of expert online courses and degrees from top universities and educators to gain accredited qualifications and professional CV-building certificates.

Join over 18 million learners to launch, switch or build upon your career, all at your own pace, across a wide range of topic areas.

Start Learning now