Question

A restaurant offers the possibility of 168 three-course dinners. Each dinner has an appetizer, an entrée, and a dessert. If the number of appetizers decreases from 7 to 5, how many fewer possible three-course dinners can the restaurant offers?

Answer 1

120

Explanation:

Let's look at it this way:

Before the change is made, there are 168 three-course dinners possible. How can we achieve that number? We have Appetizers, Entrees, and Desserts. We can reach 168 by saying:

`AxxExxD=168`

We know there are 7 appetizers, so `A=7`, and so:

`7xxExxD=168`

`ExxD=24`

We can now multiply in the new number of appetizers, `A=5`:

`5xx24=120`

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Notice that we could have simply said:

`168/7xx5=120`