Opening the iTunes Store.If iTunes doesn't open, click the iTunes application icon in your Dock or on your Windows desktop.Progress Indicator
Opening the iBooks Store.If iBooks doesn't open, click the iBooks app in your Dock.Progress Indicator

iTunes is the world's easiest way to organize and add to your digital media collection.

We are unable to find iTunes on your computer. To download and subscribe to Brain Teasers by Khan Academy, get iTunes now.

Already have iTunes? Click I Have iTunes to open it now.

I Have iTunes Free Download
iTunes for Mac + PC

Brain Teasers

by Khan Academy

To listen to an audio podcast, mouse over the title and click Play. Open iTunes to download and subscribe to iTunes U collections.


Random logic puzzles and brain teasers. Fun to do and useful for many job interviews!

Customer Reviews


These videos are extremely helpful In understanding complex ideas.

Re: Very un-rigorous

**Also potential spoiler alert**

The simple explaination that all factors are paired in numbers that are perfect squares is a simple language equivalent to the rigorous proof. These are meant to give a simple explaination to what appear to be complex problems, and do a very good job of that. The explainations of all the problems are complete but not frivolous.