To think that this sum is super simple

[PeerieBreeks]

and can't understand how so many people on Facebook have it so completely wrong (and can justify it to themselves).

Without adding your reasoning, tell me what you think the answer is.

It looks straight forward as he's made £10 on each transaction, making the answer a profit of £20, but I've been caught out by these seemingly easy maths questions before!

Doris - before I had it explained in a different way, my brain worked it out as 'he made ten, he lost ten, he made ten' and I ended up with 10 as the answer. Now I know how to work it out my original working seems daft but it made sense at the time

If it was so straightforward it wouldn't have warranted a thread grin Some people read something and get it first time, some don't.

I wonder if OP thought it would run to 14 pages of if she thought it go something like:

20
20
20
10
Short explanation post.
Oh, I see
20
20
What do you expect if you go on Facebook?

Followed by the mumsnet classic:

I asked my 5 year old DD and she said 20!

Well I can't work out why some people enjoy being smug. It's not a nice quality but that's just my dumb opinion.

With the cost of keeping a horse he’s probably about £5k down😂.

Oh and I found it obvious that it was $20. But then others find it obvious how to fix a car engine, sew an item of clothing, bake a cake without a crater in the middle or howto male and keep loads of friends .

*make!

$20 profit.

His total spend was 60+80 = 140

His total income was 70+90 = 160.

So 160-140 = gives $20 of profit.

bake cake without a crater in the middle

Witchcraft

I have an A Level in maths and a degree in science. I'm ashamed to say this took me longer to calculate that it should do but I got there in the end (I think) - $20??

I'm a maths graduate and got 20 thankfully. I did take my time to ensure I was right!
So easy to make silly mistakes in maths.

I'm ashamed to say this took me longer to calculate that it should do
You shouldnt be ashamed :-). I reckon its a lot better to have to take a minute, to be sure, and get it right, than to be sure its simple and get it wrong!

I agree with $20 for the horse sum.

The one that really confuses me (I'm not good at maths) is the T-shirt one:

You see a T-shirt for £97. You can't afford it, so you borrow £50 from your mum and £50 from your dad, which equals £100. You buy the T-shirt and get £3 change, so you give your dad £1 and your mum £1 back. You keep the other pound. So now you owe your mum £49 and dad £49. 49+49 =98 + your £1 =99. Where's the missing £1?

Oh god help me....

@Dipitydoda

With the cost of keeping a horse he’s probably about £5k down😂.

At least!

But I get $20

He’s up twenty

@RunYouJuiceBitch

I always find those ones confusing, too. I think it's because it's designed to confuse, rather than being simple maths - you're actually trying to solve a problem that doesn't exist, but rather trying to get two different sums to match, if that makes sense?

So I think:
You now owe both parents £49 each.
2x £49 = £98.

The £100 is no longer relevant, you now have borrowed £98 as you paid back £1 each.
The cost of the T-shirt is £97, plus your £1 change = £98.

So £49+£49=£98, and £97 + £1 also = £98.

Or, the sum in the question is written slightly incorrectly - you would minus off £1 because you owe £49 + £49, but have £1.
£49 + £49 - £1 = £97. (The cost of the T-shirt).

If that actually makes any sense?

I'd say he broke even. He "lost" 60 st the start and got back 70 so he's only up 10. Then he spent 80 and sold it for 90 so it ends up being even.

I'd say he broke even. He "lost" 60 st the start and got back 70 so he's only up 10. Then he spent 80 and sold it for 90 so it ends up being even.

Oh, God.

You are correct as far as "he's only up 10".

If he then spends 80, and sells it for (ie gets) 90, he's up another 10.

Hence 20 profit.

Badlad - "You are correct as far as "he's only up 10".

If he then spends 80, and sells it for (ie gets) 90, he's up another 10.

Hence 20 profit."

If he spends 80 that means he's spent the 10 he had plus another 70 and then gets 90 for it - ah I see so it's 20 profit.

It's lucky I have an accountant

You are forgiven, seeing as you have a Captain Picard username.

£10 profit surely?

I'm rubbish at maths, but I realised straight away that it would be easier for me to work out if I started with an imaginary actual amount of money to spend, rather than dealing with more abstract gains and losses. So I started with $100 and then found out how much more than $100 I had at the end. $20.

£10 profit surely?

Should we start re typing the explanations, reposting the clicky links with all the pretty bits, or just allow that some people only read page 1... and then their post looks strange when it appears on page 14