I don't know how
In a row of five squares, each square is to be colored either red, yellow, or blue, so that no two consecutive squares have the same color, and at lest three of the squares are red. How many ways are there to color the five squares?
The only way for 3 squares to be colored red is if the first, third, and last squares are red.
This means that the two remaining squares (second and fourth) must be either red or blue.
So, there are \(2 \times 2 = \color{brown}\boxed{4}\) ways to color the five squares.