Lesson 7

The number of \(k\)-combinations is called the binomial coefficient (we will soon learn where this name comes from). This is an important function that frequently appears in combinatorics. It is written as \({5 \choose 3}\). The illustration below explains the formula for \({5 \choose 3}\): \[3!{5 \choose 3}= \frac{5!}{(5-3)!}\ .\]

You can find the value of the function even in Google.

Of course, you can also use Python.

from math import comb

print(comb(5, 3))

10