Permutation question

Question

A car dealership has 5 different models of cars. 3 are blue, 1 is green, 1 is red. In how many ways can the cars be displayed in a straight line if no two blue cars can be next to each other?

Answer 1

Let’s look at each position,

blue. green/blue. blue. green/blue. blue.

1. 2. 1. 1. 1. = 2 combinations if blue is not unique

3. 2. 2. 1 1. =. 12 combinations if blue cars are

unique