Question

To complete your spring schedule, you must add Calculus and Physics. At 9:30, there are three Calculus sections and two Physics sections; while at 11:30, there are two Calculus sections and three Physics sections. How many ways can you complete your schedule if your only open periods are 9:30 and 11:30?

Answer 1

You can complete your schedule in 13 different ways.

Explanation:

You initially have two general options:

1) You can take Calculus at 9.30 and Physics at 11.30 OR

2) You can take Physics at 9.30 and Calculus at 11.30.

Let's examine each option:

1) If you take Calculus at 9.30 you'd have 3 options (since there are 3 Calculus sections), and then you'd have 3 options at 11.30 to take Physics. This makes 3 x 3 = 9 options.

2) If you choose to take Physics at 9.30, you'd have 2 options and then you'd have 2 Calculus options at 11.30. This makes 2x2 = 4 options.

Since you can take either option one OR two, we will sum up both results, and therefore you have 9 +4 = 13 different ways to complete your schedule.