Entertaining Math Problem

Yes, there is such a thing – I saw someone using this as their signature on a message board, and I found it entertaining. The first time I read it, I was baffled that someone had done something like this – then I saw the error. Can you see it?

a+b=c
4a-3a+4b-3b=4c-3c
4a+4b-4c=3a+3b-3c
4(a+b-c)=3(a+b-c)
4=3

For those who are curious, here’s the answer – highlight it with your mouse to read.
The major problem is that since a+b=c, a+b-c=0. The second-to-last line basically says 4*0=3*0 – and you can’t cancel out zeroes with division in the same way that they cancelled out a+b-c. The problem really says 0=0, which is true.

Yes, I am a Computer Science geek, but I’m also a Math geek (it’s my minor).

This entry was posted in Uncategorized. Bookmark the permalink.

2 Responses to Entertaining Math Problem

  1. Gowerlypuff says:

    There are a few of them. I like:

    x = 1
    x^2 = x
    x^2 – 1 = x – 1
    (x+1)(x-1) = x-1
    x+1 = 1
    x = 0
    => 1=0

  2. Alex says:

    It’s December 11!

Leave a Reply

Your email address will not be published. Required fields are marked *

*

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>