Mental Floss 71





The answer to last week’s question is. Q: You are in the centre of an island that is a kilometre long and half a kilometre wide. The vegetation is very dry from a long drought. Suddenly it catches fire at one end of the island, and a strong wind is blowing it towards you, burning the whole width of the island. There’s no beach, only steep cliffs, and the sea is full of sharks. What can you do?

A: Set fire to the other half of the island then walk behind the fire on to the burnt ground.

This week’s lateral thinking challenge is.

Q: There is a barrel with no lid and some beer in it. “This barrel is more than half full,” said Chuck. “No it’s not,” say Joe. “It’s less than half full.” Without any measuring implements and without removing any beer from the barrel, how can they easily determine who is correct?

The answer, along with a new challenge next week.



In the interim …. Have a very Merry Christmas!



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About the Author

Frank Connolly is the Principal of “Think Quick”, a business that adds value through thinking differently. His work history covers all sectors and includes initiatives that have yielded bottom line benefit in the 10’s of millions of dollars.

Current clients range from Exxon-Mobil to Government Depts within Australia to Global NGO’s.

Much of his working life has been split between Australia, the South Pacific and Asia where he has trained and facilitated Lateral Thinking techniques, and been acknowledged by Edward de Bono as one of the foremost practitioners of the de Bono thinking methods worldwide.

Frank believes strongly that if we can improve the way we think, the actions that follow also improve.

Comments (2)

  1. Jabr Alnoaimi :

    I can think of three ways;

    1- With the span of a hand they could measure the depth from the rim of the barrel to the surface of the liquid and then compare this with the height of the barrel as measured again with the span of the hand.

    2- If their ears could detect slight changes in tone, one could tap the barrel with the edge of a coin starting from the bottom of the barrel and listen to when the tone changes when reaching the surface of the liquid. Mark this point and then compare its height with the height of the whole barrel using the span of a hand as a measure.

    3- If there is a half size barrel that is full of beer then it can be poured into the original barrel. If it fills it and some remains then Chuck is right. If, however, the original barrel does not fill to the rim then Joe is right.

    Thank you and a happy holiday

  2. Konnn Zucknofff :

    The easiest way to solve the question would be to knock on the side of the barrel with a knuckle, moving gradually from top to bottom(or vice versa) and note when the responding sound changed – that would indicate the level of the beer inside. Being a barrel shaped container if the level at which the tone changed was above the mid-point of the barrel, it would be more than half full & if it was lower, less.


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