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!
October 9th, 2008 at 9:48 pm
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
October 12th, 2008 at 7:30 pm
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?
October 12th, 2008 at 7:51 pm
light the cord at both ends
October 12th, 2008 at 7:53 pm
What about setting fire to both ends at the same time?
October 12th, 2008 at 7:55 pm
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 As usual, I’m keeping your comments unpublished not to spoil the game, but I’m going to approve them soon.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!
October 12th, 2008 at 11:29 pm
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.
October 12th, 2008 at 11:30 pm
My mistake, let it burn for 15 minutes then apply water.
October 13th, 2008 at 8:33 am
I would imagine that you should start burning the cord at both ends at the same time in order to get 15 mins.
November 19th, 2008 at 7:44 am
burn at the middle