Here is a nice math problem!

[Isabella Hime]

A friend on skype offered a promotion to who could find the correct answer..

His post:

A kid borrows from his sister 50 bucks and from his cousin another 50 bucks, now he has 100 bucks. He buys a shirt with 97 bucks and receives as change 3 bucks.
He gives his sister back 1 buck and his cousin another 1 buck while 1 buck remains to him. So he now owes 49 bucks to each one of the borrowers.
Now the tricky part: 49 bucks + 49 bucks = 98 bucks + 1 buck in his pocket = 99 bucks
Where the fuck is 1 buck?????

 

[Lil Pom]

 

[Isabella Hime]

Apparently the answer is deer..

 

[Shiri]

I am so baffled.

 

[Gwazi Magnum]

I'm not sure how the exact math is meant to be shown, but you're going at it wrong.

You got the 100 Bucks lent to him.
This is it's own entity, which I'll represent as -100.
Negative because it's debt.

-100 Debt/+100 Cash

So, with his +100 of current cash he buys the shirt.
100 - 97 = 3. So we're at +3 Currency.

-100 Debt/+3 Cash & 97 Spent

1 Dollar is kept, two dollars get's given.
Debt becomes -98.

-98 Debt/+1 Cash & 97 Spent

97 + 1 = 98
98 - 98 = 0

 

[Isabella Hime]

Aww.. you got it right away.. was hoping to confuse everyone!

 

[Dervish]

The additional 98 dollars is separate from what he borrowed. The 3 in change was a part of the original 100, and he effectively returned 2 dollars from the original payment, making the loans in practice 49 dollars each, with .50 cents each to amount for the dollar he kept.

In essence, the mystery dollar is a red herring. The original sum more or less worked out to 49.50 from the loaners, or 99 dollars. Since he paid some back with the original sum, it makes the additional money he will pay back a lesser value than the original loan since it's like they never gave him the extra two dollars in the first place.

Best explanation I can give. Math isn't my forte.

 

[Marchosias]

This reminded me vhy math was my worst subject in school... but I suspected it vas a trick question! :P

 

[Gwazi Magnum]

In essence, the mystery dollar is a red herring. The original sum more or less worked out to 49.50 from the loaners, or 99 dollars. Since he paid some back with the original sum, it makes the additional money he will pay back a lesser value than the original loan since it's like they never gave him the extra two dollars in the first place.

Best explanation I can give. Math isn't my forte.

 

[Dervish]

I didn't work it out on paper, but the .50 cents is from the dollar he kept. Technically, wouldn't he owe that back still?

 

[Gwazi Magnum]

I didn't work it out on paper, but the .50 cents is from the dollar he kept. Technically, wouldn't he owe that back still?

Yes... But the wording is confusing me completely. :/

I mean, clearly we both reached the same conclusion.
It just looks like our methods of getting there were so different that your method is looking foreign to me. XD

 

[Isabella Hime]

We should find more math problems..

 

[foodforpigs]

Math Riddles: Try to answer these brain teasers and math riddles

The problem posted in this thread is a variation of Riddle #4.

EDIT: Also, avatar related