A mini license plate for a toy car must consist of two numbers followed by a letter. Each number must be a 7, 8 or 9. Each letter must be a C, A or R. Repetition of digits is NOT permitted.
Use the counting principle to determine the number of points in the sample space.
Construct a tree diagram to represent this situation.
List the sample space.
Determine the exact probability of creating a mini license plate with an R. Give solution exactly in reduced fraction form.