Details explanation needed please!

[bizimath]

Three red and three blue flags are arranged randomly along a wire. What is the probability that the six flags alternate in color?

Answer is 1/10.

Thank you.

 

[Harry_the_cat]

Three red and three blue flags are arranged randomly along a wire. What is the probability that the six flags alternate in color?

Answer is 1/10.

Thank you.

There's only two ways that can happen:
RBRBRB or BRBRBR

Can you find P(RBRBRB)?

Use the multiplication principle for probability.