Post me your hardest maths question you know

[Lightnix]

Okay, this one is a mind****

3 friends go to a restaurant.

They spend a total of 25 pounds, but only have 10 pounds each on them. They pay the waitress, who, being a crafty one, takes 2 pounds in tips. so she gives each of them one pound as change.

Therefore they each spend 9 pounds, as 10-1 = 9.

However (9x3) -[the amount they each spent]- +2 -[the amount the waitress took in tips]- = 29.

So, where did that last pound go?

Mhm

Well clearly she's short changed them even more than she said she did the crafty bint.

 

[Cybermyk]

Okay, this one is a mind****

3 friends go to a restaurant.

They spend a total of 25 pounds, but only have 10 pounds each on them. They pay the waitress, who, being a crafty one, takes 2 pounds in tips. so she gives each of them one pound as change.

Therefore they each spend 9 pounds, as 10-1 = 9.

However (9x3) -[the amount they each spent]- +2 -[the amount the waitress took in tips]- = 29.

So, where did that last pound go?

Mhm

9x3 is the amount they spent including the tip

Bill = £25 - Tip = £2 - Change = £3

Totals £30

 

[Shayper]

9x3 is the amount they spent including the tip

Bill = £25 - Tip = £2 - Change = £3

Totals £30

Edit: And no I'm not bad at maths, it was my mates problem, we've had a few, I was MIND******, and decided to post it

Even though I do a degree in maths, I can still be outfoxed by drunken logic

 

[dl8860]

0.9 recurring equals 1. end of

 

[Aod]

0.9 recurring equals 1. end of

indeed - anyone who thinks otherwise doesn't correctly understand the concept of infinity.

 

[nightwish]

Well said dl8860 and Aod! I can't believe people still don't get this... It's one of the simplest mathematical proofs you can get people!

 

[Angelos_n]

indeed - anyone who thinks otherwise doesn't correctly understand the concept of infinity.

The thing thats possibly wrong with this equation is the assumption the equation makes i.e 1/3 = 0.3r is assuming that you are giving the example of "1/3 of 1" therfore the answer ofcourse will be 1 that the whole point. if you just said 1/3 it could mean anything. when you put 1 / 3 in a calc as i stated earlier due to the infinite number of bits it would need to store it simply rounds it up, in truth 1 / 3 cannot be computed, the equation cannot be finished. so mathematicians got lazy and said lets just round it. but i refuse to beleive the answer is 1


i could say well 1 / 3 = 0.3 r
and 2 / 3 = 0.6r

and 3 X 0.3r = 0.9r

therefore 0.9r = 0.9r

and not 1 you cant just add that 0.x1

 

[D.P.]

Greater minds than anyone posting on this board have debated back and forth over this 0.9r=1 concept and never reached an agreed conclusion, it's not something that's going to be miraculously solved by an argument over whether 0.9r multiplied by 10 is 9 or 9.9r.

wrong, very few mathematicians ever argue this, only Internet trolls and an high school students.

 

[Benihana]

How long is a piece of string?

Twice half its length

 

[ntg]

How about this one -

You travel to america at 100km/h. You then travel back at a constant speed. The average speed for the entire journey is 50km/h. What was your speed in returning from america?

heh heh heh
arent i funny

If I travel in reverse would that count as -X kilometres/hour? I could solve it that way!

 

[Voices]

How to make ends meet.

 

[AJK]

The thing thats possibly wrong with this equation is the assumption the equation makes i.e 1/3 = 0.3r is assuming that you are giving the example of "1/3 of 1" therfore the answer ofcourse will be 1 that the whole point. if you just said 1/3 it could mean anything.

What? 1/3 is the mathematical representation of "one divided by three". Where do you get the idea of 1/3 "assuming" anything?

 

[Amleto]

i could say well 1 / 3 = 0.3 r (1)
and 2 / 3 = 0.6r

and 3 X 0.3r = 0.9r (2)

therefore 0.9r = 0.9r

and not 1 you cant just add that 0.x1

using what you have written:

(2): 3 X 0.3r = 0.9r.

subst (1) into (2): 3 X (1/3) = 0.9r
but 3 X (1/3) = 1 therefore
1 = 0.9r.

oh, thy double edged sword! How thy hath slane one.

 

[Inquisitor]

Is ZFC consistent?

 

[SexyGreyFox]

wrong, very few mathematicians ever argue this, only Internet trolls and an high school students.

First time I've been in this debate but using an old mans wisdom, if I was asked to travel 1 mile until I hit a wall but I only ever went 0.9999r mile then I will never hit the wall.
I have never gone 1 mile therefore 0.9999r can't equal 1

 

[Knubje]

This thread has reminded me that I really dislike maths.

 

[Deleted member 651465]

Find the √BATMAN

 

[Inquisitor]

First time I've been in this debate but using an old mans wisdom, if I was asked to travel 1 mile until I hit a wall but I only ever went 0.9999r mile then I will never hit the wall.
I have never gone 1 mile therefore 0.9999r can't equal 1

If you "only ever went 0.9r miles" when you would have travelled 1 mile and hit the wall. They are mathematically equivalent, whether your intuition agrees or not.

 

[Morbius]

First time I've been in this debate but using an old mans wisdom, if I was asked to travel 1 mile until I hit a wall but I only ever went 0.9999r mile then I will never hit the wall.
I have never gone 1 mile therefore 0.9999r can't equal 1

If two real numbers are different, then you can always find a third number that sits between them.

What number sits between 0.9r and 1?

 

[D.P.]

First time I've been in this debate but using an old mans wisdom, if I was asked to travel 1 mile until I hit a wall but I only ever went 0.9999r mile then I will never hit the wall.
I have never gone 1 mile therefore 0.9999r can't equal 1

wrong, you will hit the wall after n infinite time.

You just aren't understanding the concept of infinity.


You also seem to have believe that 0.9r is a different entity to 1.

0.9r means exactly the same thing as 1, it is just 2 different symbols that mean the exact same thing.
By definition, 0.9r = 1. This is absolute true in every sense of the meaning.

What you are arguing is 1 != 1. Which is just absurd.

1=1
1= 0.9r


0.9r does not mean 0.999999999999999999999999999999999999999999999999999.... with a very long repetition of 9s. 0.9r means 1.

Here is another example:
X = 1
Y = 1
X = Y. You are trying to argue that this doesn't hold, of course it holds, by the very definition. X and Y are just different symbols to represent the same thing.
Just because a number has two different symbolic representation doesn't mean they are different.


Its like giving someone a nickname, when you use their full name or their nickname you still refer to the same person, not two different people.