What are the odds of getting 3 rock paper scissors in a row alike?

There are 3³ possibilities for playing 3 rounds in rock paper scissors (3 choices in every round). 

Draw a tree diagram of every round and (assuming that the three choices can be played in an random order as long as they are different), the options are 6. 

P(RPS)=6/27=0.22 

Hope I helped :) 

Set up a system of equations