Permutations & Cominations:

Your friend is having a party and has 15 games to choose from. There is enough time to play 4 games. In how many ways can you choose the four games?

32760 ways

Step-by-step explanation:

Suppose we all want to play different games, so 4 different games. At the first game there are 15 choices, at the 2nd game there are 14, the 3rd one there are 13 selections, and at the last there are only 12 options to select from. Then the total number of ways you can choose the 4 games is

15*14*13*12 = 32760 ways