# Counting Theory

Learn about counting theory.

StartCounting Theory: Lesson

Lesson 1 of 1

- 1There are three types of people, those who can count and those who can’t! Counting the number of ways to perform a task is simple — until the number of choices gets too large. One fundamental cou…
- 2It takes some mathematical insight to figure out how many elements satisfy a property without enumerating all of them. Here are some standard techniques. * The Sum Rule: If there are n(P) ways to …
- 3What if there are many groups, and not just two? For example, a test consists of six multiple-choice questions. Each question has four possible answers. How many possible answer combinations are th…
- 4The choices we have seen till now are from disjoint groups. For example, the same food item is not both a crust and a topping. The two groups are
*independent*of each other. Let us look at another… - 5One very interesting number pattern is Pascal’s Triangle (named after Blaise Pascal, a famous French Mathematician and Philosopher). To build the triangle, start with a ‘1’ at the top, then continu…
- 6#### Bit strings A bit string is a sequence of bits (0 or 1). For example, 00001111 and 1011010 are bit strings of length 7. Bit strings can be used to represent sets or to manipulate binary data….

## How you'll master it

Stress-test your knowledge with quizzes that help commit syntax to memory