A mini license plate for a toy car must consist of a number followed by two letters ...

2. A mini license plate for a toy car must consist of a number followed by two letters.  Each letter must be a C, A or R. Each number must be a 3 or 7. Repetition of letters is 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 a C. Give solution exactly in reduced fraction      form.