Exercise 12 Page 887

We are given the choices of burrito orders at a burrito stand. We need to write the choice cheese and/or salsa as separate stages, because we want to allow for the possibility of choosing both cheese and salsa. Therefore, there are four stages of ordering a burrito.

• Beans (B), pork (P), or chicken (Chi)
• Rice (R) or no rice (NR)
• Cheese (Che) or no cheese (NChe)
• Salsa (S) or no salsa (NS)

We will draw a tree diagram to represent the sample space for burrito orders.