## Let’s count – Partitions

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 …

## The inclusion/exclusion principle: counting unions

How to count the number of elements of a finite union of sets? This is quite easy when you deal with two sets: just count the number of elements of …

## Some examples

Let us see how to apply the Inclusion/Exclusion Principle…

## Let’s count – Sharings into nonempty sets

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 …

## How to count, and what?

The purpose of this MOOC is to let you solve problems of counting like: – In how many ways can one form a hand of 5 cards chosen among 52? …

## Let’s count – Counting intersections

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 …

## Let’s count – Derangements

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 …

## Let’s count – Uniform probability

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 …

## Let’s count – Counting unions, 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 …

## Let’s count – Counting unions, 2

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 …

## Let’s count – The basic principles of combinatorics, 2

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 …

## 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 …

## Let’s count – Distribution of objects, 2

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 …

## Let’s count – Distribution of objects, 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 …

## The Division Principle

The Multiplcation Principle is suitable to count sets that are obtained through an ordered sequence of steps. When the order does not count, it cannot be directly applied since from …