The last **riddle** was too easy for you, as I see. What about this one? You have a **cord** and a lighter. If you fire the cord at the end, it will take half an hour to burn. How do you measure exactly 15 minutes using only these two things? Note that the cord does not burn at a constant speed, that is, some parts burn faster, other parts – slower.

Please, if you want to solve the riddle yourself, don’t read the comments to this **brain game**, because you may find the answer already written there. I will publish the correct answer in the next brain game. You are always welcome to ask questions about the task in case something is not clear. But, sorry, I will not answer leading questions.

And the answer to the brain game about flowers is three flowers – one rose, one violet, and one tulip. Jed, Amanda, Arsh, Ahoo, thanks for your participation, you’re right!

If you fire both ends of the cord at the same time when the flames meet it will have been 15 minutes because you’re burning it twice as fast 🙂

Cut the cord in half, and burn both halves.

Measure the amount of time each takes to burn, and take the average.

Is that right?

light the cord at both ends

What about setting fire to both ends at the same time?

Hi, everybody! As usual, I’m keeping your comments unpublished not to spoil the game, but I’m going to approve them soon. Thanks for your participation!

This is so easy.

You need a glass of water and a stopwatch.

Light the cord and let it burn for exactly forty-five minutes then dump the water on the flame. When the cord dries you will have exactly 15 minutes of burn time remaining.

My mistake, let it burn for 15 minutes then apply water.

I would imagine that you should start burning the cord at both ends at the same time in order to get 15 mins.

burn at the middle

Burn from both ends, will take 15 minutes to consume rope, regardless of burn inconsistent rates.

This is quite a up-to-date info. I’ll share it on Delicious.