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.


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


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


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


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

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 :grin:


Wow this is awesome :smile::smile: 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! :smiley:


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!


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


Don't make me do math. :stuck_out_tongue:


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


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.


New brain teaser! Difficulty 6/10.

Can you prove that seven is half of twelve?

Remember to put your answers in [spoiler][/spoiler] tags!


7 = 12
Because of absolute infinity!


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


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


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


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 :grin:

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 :slight_smile:

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' :open_mouth:


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

Apparently the trig one is extremely mean