A mini license plate for a toy car must consist of a two letters followed by a one digit odd number. Each letter must be a J or a Z. Repition of letters is permitted.
1. Use the counting principle to determine the number of points in the sample space.
2. Construct a tree diagram to represent this situation. List the sample space.
3. Determine the exact probability of creating a mini license plate with a z. Give solution exactly in reduced fraction form.