You and 3 friends go to a concert. In how many different ways can you sit in the assigned seats?
Assuming there are no restrictions on where each person can sit, there are 24 different ways you and your friends can sit in the assigned seats.
To see why, imagine that each of you has a different color shirt: red, blue, green, and yellow. You can arrange yourselves in any order, so there are 4 ways to choose who sits in the first seat. Then, there are only 3 people left to choose from for the second seat, so there are 3 ways to choose who sits there. Similarly, there are 2 ways to choose who sits in the third seat, and only 1 person left to sit in the fourth seat.
Therefore, the total number of ways you can sit in the assigned seats is:
4 x 3 x 2 x 1 = 24