Foundation June 2017 Paper 1 Q8
8. A vending machine sells drinks.
Each drink costs 50 pence.
A sign on the machine shows the coins that can be used to buy the drinks.
| Drinks: 50p This machine accepts 50p, 20p, 10p and 5p coins only NO CHANGE IS GIVEN |
Complete the table to show the 13 different ways of paying the exact amount for a drink. [2]

The machine has a display that shows how much cash has been put in.
The machine resets the display to £0.00 after each drink is taken.
The cash container in the vending machine is emptied every night.
When it was emptied, the cash container contained the following coins:
| 50p | 20p | 10p | 5p |
|---|---|---|---|
| 10 coins | 15 coins | 31 coins | 20 coins |
Work out the greatest possible number of drinks that could have been sold.
You must state any assumption that you make. [5]
Number of drinks sold …………
Assumption made …………
| Scheme | Marks | Comments | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| B2 | B1 for any 3 correct rows |
| Scheme | Marks | Comments |
|---|---|---|
| (i) Appropriate strategy e.g. attempting to work out the total amount taken | S1 | |
| \(\left(\dfrac{10}{2} + \dfrac{15}{5} + \dfrac{31}{10} + \dfrac{20}{20}\right)\) or 50 × 10 + 20 × 15 + 10 × 31 + 5 × 20 or (£)5 + (£)3 + (£)3.1(0) + (£)1 ( = (£)12.10) | M1 | May be seen in stages. |
| £12.10 ÷ 0.5(0) or 1210 ÷ 50 or equivalent | M1 | FT ‘their 12.10’ in £ or p but units must be consistent |
| 24 | A1 | CAO |
| Any valid assumption stated e.g. ‘The fewest number of people possible overpaid’ or ‘Only one person overpaid’ or ‘The machine always dispensed a drink when money was inserted’ ‘The machine broke down after 10p had been inserted’ | E1 | Allow eg ‘Someone paid more than 50p for a drink.’ Or ‘Someone paid with three 20p coins’ |
| (ii) Any valid impact based on their stated assumption e.g. ‘The number of drinks sold may be lower’ | E1 | |
| (8) |
Alternative
Alternative Method for (b)(i)
| Scheme | Marks | Comments |
|---|---|---|
| Appropriate strategy eg working with multiples of 50p or attempting to work out the subtotal amount taken for each type of coin | S1 | |
| Working out the number of drinks bought using the 50ps and at least one of the other coins seen or implied or for using any two of the other coins eg 10 and 7 or 10 and 6 or 10 and 2 | M1 | |
| Summing ‘their numbers of drinks’ found from all the coins eg 10 + 7 + 5 + 2 or 10 + 7 + 1 + 4 + 2 or 10 + 6 + 6 + 2 | M1 | |
| 24 CAO | A1 |