General / Off-Topic 7x13=28

[Alien]

 

[Para Handy]

 

[Chris Simon]

So you like weird maths, ey?
How about this one:

Three friends were out for a cup of coffee and some snacks.
When they were finished, waitress handed them a 30 quid bill. So they each paid £10 and were about to leave when she came back.
She apologized that she had made a mistake and the bill is only £25 and she gave them their 5 pounds back.
Because it was nice of her and £5 is not easily divisible by 3 anyway, each friend took back one pound and gave her the remaining two as a tip.

So...
That means that each one in fact paid £9 - that is £27 together plus that £2 tip, which sums up to a £29 total.

Where the hell did that one pound go?

 

[Alien]

So you like weird maths, ey?
How about this one:

Three friends were out for a cup of coffee and some snacks.
When they were finished, waitress handed them a 30 quid bill. So they each paid £10 and were about to leave when she came back.
She apologized that she had made a mistake and the bill is only £25 and she gave them their 5 pounds back.
Because it was nice of her and £5 is not easily divisible by 3 anyway, each friend took back one pound and gave her the remaining two as a tip.

So...
That means that each one in fact paid £9 - that is £27 together plus that £2 tip, which sums up to a £29 total.

Where the hell did that one pound go?

I've heard of this one before, and it's all in how you explain it.
If you explain it as 3x9+2=29 then yes, there is a 1 missing.
But when explained correctly, it all adds up.

The bills was 25
Each friend got an extra 1, so that's 3
The waitress got 2
25+3+2=30

EDIT: I told this puzzle to two teachers, and they ended up arguing over it

 

[Chris Simon]

I've heard of this one before, and it's all in how you explain it.
If you explain it as 3x9+2=29 then yes, there is a 1 missing.
But when explained correctly, it all adds up.

The bills was 25
Each friend got an extra 1, so that's 3
The waitress got 2
25+3+2=30

EDIT: I told this puzzle to two teachers, and they ended up arguing over it

Hahah, yes. Of course the "trick" in this riddle is to distract the listener.
It's not the math that's wrong, it's the way you lay the problem before them.

 

[Patrick_68000]

So you like weird maths, ey?
How about this one:

Three friends were out for a cup of coffee and some snacks.
When they were finished, waitress handed them a 30 quid bill. So they each paid £10 and were about to leave when she came back.
She apologized that she had made a mistake and the bill is only £25 and she gave them their 5 pounds back.
Because it was nice of her and £5 is not easily divisible by 3 anyway, each friend took back one pound and gave her the remaining two as a tip.

So...
That means that each one in fact paid £9 - that is £27 together plus that £2 tip, which sums up to a £29 total.

Where the hell did that one pound go?

In reality as the bill is £25, each paid £8. And the remaining pound helps to pay the entire bill.

 

[Alien]

So you like weird maths, ey?
How about this one:

Three friends were out for a cup of coffee and some snacks.
When they were finished, waitress handed them a 30 quid bill. So they each paid £10 and were about to leave when she came back.
She apologized that she had made a mistake and the bill is only £25 and she gave them their 5 pounds back.
Because it was nice of her and £5 is not easily divisible by 3 anyway, each friend took back one pound and gave her the remaining two as a tip.

So...
That means that each one in fact paid £9 - that is £27 together plus that £2 tip, which sums up to a £29 total.

Where the hell did that one pound go?

I've heard of this one before, and it's all in how you explain it.
If you explain it as 3x9+2=29 then yes, there is a 1 missing.
But when explained correctly, it all adds up.

The bills was 25
Each friend got an extra 1, so that's 3
The waitress got 2
25+3+2=30

EDIT: I told this puzzle to two teachers, and they ended up arguing over it

Hahah, yes. Of course the "trick" in this riddle is to distract the listener.
It's not the math that's wrong, it's the way you lay the problem before them.

As if you (ie anyone interested) needed further explanation of how this puzzle works ... and because this might be interesting .... VSauce's Kevin explains it

I had seen this video when it first came out, but as if by magic, Youtube recommended it today :/

 

[Phongsalt]

it went down the back of the sofa.