A test of your common sense

Hi TangleI knew the one about the choice of doors in the game show....but I don't know the one with the Bridge hand.Logic suggests that it shouldn't make a difference, but knowing the topic of this thread and the game show example, I'm guessing it certainly does...though I can't for the life of me figure it out!Here's a relatively simple puzzle that often seems to fox people (used to best effect with friends in the pub when they've had a few drinks and their thinking has slowed......)Three men go to a restaurant for a meal. Each has a 10 note. They choose a meal that costs each of them exactly 10. The waiter collects the three 10 notes and heads off to the till where he remembers that it is a block-booking for which they receive a 5 discount.Looking in the till he finds he only has 1 coins. He can't share 5 x 1 coins fairly amongst the three men. He scratches his head and thinks. He could keep the 5 discount - however he is (reasonably) honest and doesn't want to do that either.So he has an idea....he'll give them 1 back each telling them he's overcharged them by a 1 each and he'll keep the other 2 as his tip,So...this means the men haven't spent 10 each but only 9. Three times nine is 27 plus the 2 the waiter has kept makes 29.........hmmm...where is the 30th pound?I've had some real fun in the pub with this one. Once I got a group of around a dozen scratching their heads with it......yet it's not difficult is it?

Spot on Percy - as you say it is posing the wording with an incorrect assumption (3x9+2(the tip)=29 whereas it should be 3x9+3(the refund)=30). Glad you weren't present in the pub to suss it out - try it next time you are in the bar and the beer has been flowing - you'll be amazed how many you'll hook with it.

Clear as mud !!!I haven't a clue how you worked those percentages out!

NO!That is NOT what Taz has said. He is not saying only experts can discuss evolution (or whatever they are expert in). what he is saying is that you can't apply everday common sense carte blanche.You should never apply 'common sense' to detailed investigations as 'common sense' from a scientific point of view is often utterly inadequate to explain reality.Common sense seems to show the Sun goes around the Earth.
Common sense seems to show that time is fixed
Common sense seems to show that matter is solid
Common sense seems to show that the speed of light can be exceeded....had enough yet?Anyone can discuss evolution (and any other subject they care to discusss). However for that person to have rational relevant content, it requires detailed study of evidence and the underlying theories of the subject so far discovered.....and defininitely NOT common sense.And THAT is the point being made here.Edited by Drosophilla, : No reason given.