From the course: Statistics Foundations 2: Probability

Unlock the full course today

Join today to access over 24,100 courses taught by industry experts.

Combinations

Combinations

- When you're giving out three cash prizes in a raffle, $10, $100, $1,000, the order in which the three winners are chosen is important. In those cases, when order is important, we use permutations, but sometimes order doesn't matter. In those cases, we use combinations. Consider this scenario. Suppose we have 12 students in a class and one team of four students is going to be chosen at random to represent the school at a prestigious competition. Olivia and Layla are sisters. They both want to be on the team together, so what's the probability they will both get chosen for the team? To solve this, we'll need to know how many combinations of four students would be possible. Combinations are different than permutations. How? Well, look at these two teams of students. In both cases, we have the same combination of students. When we create teams, the order in which we list the names doesn't change the nature of the team. So…

Contents