You are Here: Home >< Maths

# Maths problem watch

1. I need help with this problem.

3 people want to buy something that costs £30. They each give £10 and send a friend to the shop to buy the item.
When the friend gets to the shop the item is on sale and now only costs £25. So he has £5 change.
Now £5 is tricky to divide between 3 people, so the friend decides to keep £2 and give £1 each back to the 3 people.

So he’s given each person £1 back which means they’ve each only given £9 towards the item. 9x3=27. The friend kept £2. 27+2=29. Where has the other pound gone?
2. (Original post by Ccilliers)
I need help with this problem.

3 people want to buy something that costs £30. They each give £10 and send a friend to the shop to buy the item.
When the friend gets to the shop the item is on sale and now only costs £25. So he has £5 change.
Now £5 is tricky to divide between 3 people, so the friend decides to keep £2 and give £1 each back to the 3 people.

So he’s given each person £1 back which means they’ve each only given £9 towards the item. 9x3=27. The friend kept £2. 27+2=29. Where has the other pound gone?
What do you think?

"Now £5 is tricky to divide between 3 people, so the friend decides to keep £2 and give £1 each back to the 3 people."
3. I’m not sure why you’ve highlighted that part? I’m aware that 2+3=5. But by giving the £3 back to the people means they only paid £9 each. 9x3=27. Which means £3 left over. And if the friend kept £2 then there’s £1 unaccounted for? And I can’t figure out how to make it add up from that perspective?
4. (Original post by Ccilliers)
I’m not sure why you’ve highlighted that part? I’m aware that 2+3=5. But by giving the £3 back to the people means they only paid £9 each. 9x3=27. Which means £3 left over. And if the friend kept £2 then there’s £1 unaccounted for? And I can’t figure out how to make it add up from that perspective?
The £2 is part of the £27, not part of the £3 that was left over.

### Related university courses

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: October 17, 2017
Today on TSR

### He lied about his age

Thought he was 19... really he's 14

### University open days

Wed, 25 Jul '18
2. University of Buckingham
Wed, 25 Jul '18
3. Bournemouth University
Wed, 1 Aug '18
Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams