## Chocolate Offer

#### Problem

To promote the launch of a new Cradbury's chocolate bar they are offering a, "buy four, get one free" deal. If each chocolate bar costs thirty pence, how much would ten chocolate bars cost?

#### Solution

If we get five for the price of four, ten will cost the same as eight. Hence ten chocolate bars will cost 8 0.30 = £2.40.

How much would seventeen chocolate bars cost?

What if you wanted to buy `n` chocolate bars?

What if it they offered a, "buy three, get one free" deal?

Can you generalise?

Problem ID: 122 (Oct 2003) Difficulty: 1 Star