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        riddles >> easy >> Make this equation true
        
(Message started by: c-dog-85 on Feb 21^st, 2003, 2:30am)

Title: Make this equation true
Post by c-dog-85 on Feb 21^st, 2003, 2:30am

Imagine the following equation written on a piece of paper:

5+5+5=550

Now where could you draw a single straight line of any length to make this equation true?

Title: Re: Make this equation true
Post by wowbagger on Feb 21^st, 2003, 3:13am

My first idea is to [hide]fold the paper such that the "50" of the right hand side isn't visible any more. Then you draw a vertical line in front of the remaining 5 to form a 15[/hide].

Title: Re: Make this equation true
Post by ninja on Feb 21^st, 2003, 3:25am

A good answer. Although not the one I had in mind, it would work. Try again, though. No folding of the paper is needed, just draw a line somewhere...

Title: Re: Make this equation true
Post by wowbagger on Feb 21^st, 2003, 6:03am

Here's a solution that works on a blackboard as well:
[hide]Draw a straight line connecting the top and left ends of one of the "+" signs[/hide].

Title: Re: Make this equation true
Post by prince on Feb 21^st, 2003, 10:35am

Of course, one could simply [hide] draw a diagonal line through the =, making it a 'not equal' sign[/hide], but I suppose you want a more creative answer.

Title: Re: Make this equation true
Post by wowbagger on Feb 21^st, 2003, 12:12pm

Prince,
your suggestion isn't a valid solution, I'd say, because it doesn't "make this equation true".

Title: Re: Make this equation true
Post by Johno-G on Feb 21^st, 2003, 4:23pm

But of course princes solution is right:
5 + 5 + 5 does not equal 550 is a perfectly correct equation. What is there about it that is NOT correct???

Title: Re: Make this equation true
Post by wowbagger on Feb 21^st, 2003, 5:15pm

on 02/21/03 at 16:23:03, Johno-G wrote:

But of course princes solution is right:
5 + 5 + 5 does not equal 550 is a perfectly correct equation.

No, it's a perfectly correct statement.
Prince's idea yields an inequality whereas the riddle asks us to "make this equation true", implying that the result is also an equation.

Title: Re: Make this equation true
Post by Wah on Feb 21^st, 2003, 10:44pm

wowbagger is right!

a few more.
add a finite line to make the equations valid.

fifty one equals one hundred and twenty
cool one: one plus one equals a hundred thousand and a hundred

Title: Re: Make this equation true
Post by Johno-G on Feb 22^nd, 2003, 11:57am

But "make this equation true" does not STRICTLY imply that the final answer HAS to be an equation - it mereley states that:
a) At present you have an equation, and
b) You must make it into SOMETHING that is true.

Note that many riddles are based upon trickery of words. If the answer was supposed to be an equation, the wording of the problem could have been more along the lines of, "make this into a true equation".

Title: Re: Make this equation true
Post by wowbagger on Feb 25^th, 2003, 4:24am

on 02/22/03 at 11:57:47, Johno-G wrote:

As you may or may not know, I'm not a native English speaker, so my understanding could well be wrong. However, according to OALD (http://www1.oup.co.uk/elt/oald/) "make +noun +adj." means "to cause sb/sth to be or become sth". Not in one of the examples given the noun changes its meaning. For this to be plausible I'd use the construct "make sth. of sb./sth." or "make sth. sth.".

Quote:

Note that many riddles are based upon trickery of words. If the answer was supposed to be an equation, the wording of the problem could have been more along the lines of, "make this into a true equation".

You have a point here. However, the trickery of words shouldn't go too far. It should preclude rather trivial answers as in the case of such "match equations".
Your alternative wording may be more easily comprehensible, but I still think that the original wording has the same meaning.

Please don't shout in your posts.

Title: Re: Make this equation true
Post by towr on Feb 25^th, 2003, 6:36am

If you draw a line anywhere in the equation it will no longer be the same equation.
So to make the given equation true perhaps we should strike out some axiom from algebra..

Title: Re: Make this equation true
Post by wowbagger on Feb 25^th, 2003, 8:29am

Sorry, I don't think I get your point, towr.
I'm not asking you to come up with the same equation, only true. What I'm trying to get across is the fact that the solution should (imho) be an equation, not an inequality, nor a relation using "less than" or the like.

Title: Re: Make this equation true
Post by towr on Feb 25^th, 2003, 9:35am

on 02/21/03 at 02:30:59, c-dog-85 wrote:

to make this equation true?

once you chance the equation, it is no longer 'this equation', but a different, perhaps still similar, equation..

It's mostly unrelated to the point you try to make.. it's just taking the riddle even more literally..

Title: Re: Make this equation true
Post by prince on Feb 25^th, 2003, 10:56am

I didn't think I'd stir up such controversy. Of course, the inequality solution is not the intended answer, but it is still a valid solution.

As towr points out, there is no way to make "this equation" true. When adding a line, we can make a different equation, or even a different statement (of inequality, in this case). As long as it is true, it fulfills the obligation of the riddle. I don't think the implication that the answer is necessarily an equation is stated, even if it is intended.

Title: Re: Make this equation true
Post by wowbagger on Feb 26^th, 2003, 4:33am

on 02/25/03 at 10:56:47, prince wrote:

I don't think the implication that the answer is necessarily an equation is stated, even if it is intended.

I suggest we just agree to differ on this point.