Question

In a sub shop, there are several topping options for creating a sandwich. Alex loves to go to this

restaurant every day for lunch and buy a sub. There are five options for meat, four options for vegetable and four options for sauce. If he tries to order a different combination of meats/
vegetable/ sauce every day, how many days will it take before he has to report one of his sandwiches? [4 marks/T]

Answer 1

80 days

Explanation:

For each of the 5 meat choices, there are 4 vegetable choices, so a total of 5·4 = 20 meat/vegetable combinations.

For each of those, there are 4 sauce choices, so a total of ...

20·4 = 80

meat/vegetable/sauce combinations.

If a different one is ordered each day, it will take Alex 80 days before he must repeat an order.