A driver needs to take his truck across a mile long bridge with a 5,000kg weight limit. This bridge happens to be one of those logic puzzle bridges which will collapse as soon as any weight over the limit is on the bridge.

The driver pulls the truck onto a conveniently placed weigh station right in front of the bridge. It reports the total weight of the truck, including the driver and everything contained in the truck, is 4,999.99kg.

The driver starts to head across. When he reaches the half-way point a sparrow flies overhead looking to land on the truck. The sparrow weighs 30g. What does the driver need to do to avoid the sparrow tipping the weight of the truck past the 5000kg weight limit?

" Lateral thinking" problems make nice conversation starters, sometimes introduce non-orthodox approach to arrive to a surprising answer and sometimes trigger questions-and-answers session between the solver and the asker, who knows the "official" solution.

However many puzzles of this kind depict a strictly theoretical situation, in  which while striving for a punch-line result the puzzle does  not provide all the conditions to make the official answer valid reaching an answer whose  veracity is easily challenged.

In our case, why should the driver worry about sparrow and decide to throw his shoes (or pass water) away, while he assumes during his mile-long drive total  absence of a car (bicycle, person, dog  etc) entering the bridge shortly after him.

Summing up: unless a lateral puzzle is highly creative and reasonably sound DO NOT POST IT - leave it for friendly gatherings where missing details can be clarified prior to throwing coconuts away. 

Posted by Ady TZIDON on 2016-08-04 10:54:04