If you used a random number generator for the numbers from $1$ through $20$ to play a game, what is the theoretical probability of getting each of these outcomes?

1. A multiple of $3$ or a multiple of $7$, P(multiple of $3$ or multiple of $7$) 

   Hint (a):

   How many possible favorable outcomes are there?

   More Help (a):

   How many total outcomes are there?

2. P(even or odd) 

   Hint (b):

   Follow the steps in part (a).

   Answer (b):

   $1$

3. P(prime or $1$) 

   Hint (c):

   There are $9$ possible correct outcomes.

4. How did you find the probabilities of these events? Be ready to share your ideas with the class.

   Hint (d):

   What method did you use to find the probabilities?