I was exchanging brainteasers with a colleague at work today and decided that I would start posting some here… just as a fun (sometimes frustrating) pastime to keep those gears turning.

**Please don’t spoil this by posting answers via comments.**

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The following two are from my friend Julia.

- An individual goes up a hill at 20mph. At what speed will he have to come down the hill to double his average speed for the entire trip?
- You have a balance scale and a bar that is 40 inches long and 40 pounds heavy. Every 1 inch increment of the bar weighs 1 pound. You are allowed to cut the bar 3 times. Where would you cut the bar in order to measure every integer from 1 to 40 using the balance scale?

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I hope you’re planning to give hints for #1 soon.

Hint for #1 below – DON’T READ IF YOU DON’T WANT A HINT.

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The average of two numbers is simply the sum of those two numbers divided by two. Average speed, however, is a rate and cannot be calculated this way.

How do I send you the answers if not through comments? :-)

Hi Deepak,

If you need affirmation that your answers are correct, you can email me : eseema@gmail.com

Thanks!

I think you need a password protected way that users can get the answer on your site… can you just whip that up please? ;)

Seema — If we can’t prove our mental muscle through posting answers in the comments, we at least need a leaderboard or something to track successful teaster-solvers.

I need incentive damn it … :)

Great website, nice tips, thanks for sharing