Answer provided, need solving details, thx

A European put has strike $18 and expires in three time steps. Using CoxRoss-Rubenstein notation, the underlying asset has S=15,u=1.2 and d=0.95. The return over each time step is R=1.1. What is the expiry value of the put at node (3,1) ? Do not include the dollar sign (\$) in your