# Challenge Math and Brain Teaser Problems!

No. A person must choose an exit from the 2 listed.
Either be fried from the sun by the magnifying glass, or be killed by the dragon.

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Ooh.. I don't know, then.. it's a toughy

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He waits until night time and then goes through the first door.

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Ah! Smart! Very smart! That's a tricky one

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Wait for it to be nighttime. The sun would have set, and the dragon would be sleeping. Ok maybe not the second part

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I have not looked at @JonnyGamer's answer but the first thing that came to mind was triangle numbers too!

Formula for n-th triangle number = n(n+1)/2

n(n+1)/2 = 210
n(n+1) = 420
nĀ² + n = 420
nĀ² + n - 420 = 0
(n + 21)(n - 20) = 0

[insert school maths explanation processes]

n = 20 years old
sorry that I haven't elaborated further, just wanted to try this quickly

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Wow this is awesome and even more lovely that you explained them ā meanwhile I was too anxious to try out the problem after not being able to get on the forum haha ā You know what, you could collect what you wrote and save it in a blog post!

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Yes! I'll do that!
I'd love to work on the blog posts with you over the summer, it's going to be a lot of fun!

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Yes! Yay I'm so glad too!!!

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Don't make me do math.

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It's 7656, I think, but I dont think you wanted to know that.

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I think you might have forgotten to divide by 2
I'm not sure

I dunno. That was honestly just a guess, cuz you do..wait...yeah.

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New brain teaser! Difficulty 6/10.

Can you prove that seven is half of twelve?

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7 = 12
Because of absolute infinity!

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The question is how 7 is half of 12. And no, that is not the answer, at least not the one I know.

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7 = 12
12/2 = 6 = 12
7 = 6
6 is half of 12
XD

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My friend made a suuuuper awesome math quiz!
click for the higher resolution

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Ooh very interesting question!

Hmm the only thing I could think of...

...was different bases, until I saw you'd put it in words rather than 7 equalling 12

If it were base twelve, 1212 would equal fourteen, in which case 7 is indeed half of 14.

I have heard of problems like "when does 11 + 2 = 1" in which case, answer is on a clock but I don't think that works for this one here. This is an interesting problem

And woah @JonnyGamer, your friend's worksheet looks really fun!! So many to choose from... one that caught my eye was the second one under the heading 'Algebra II & Geometry'

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Yeah! That one is really fun!
(I actually just solved it today! )

Apparently the trig one is extremely mean

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