Solution for Section 6.4 Question 4a

4. a) Consider the possible dish combinations in two parts:

• you could choose four dishes that did not include the chicken with noodles dish (choose 4 dishes out of 26), or
• you could have the chicken and noodles dish (and hence also the beef and black bean dish) and then choose two other dishes (choose 2 dishes out of 25).

Since these two situations cannot overlap, you can apply the addition rule.

The total number of ways in which to choose four different main dishes (assuming that if you choose the chicken with noodles, you also take the beef and black bean) is

Back to Section 6.4