Posts will be added to this page in groups of ten as they accumulate
Teasers on top/Answers below
1. A man looks at a portrait and is heard to say:
“Brothers and sisters have I none …
and this man’s father is my father’s son.”
Whose portrait is it?
2. You are given five seemingly identical balls and told that all are of identical weight except one. Using a balance like the one above, identify the odd ball and say whether it is under or over-weight. You are allowed no more than three (3) weighings.
3. You visit a land where there are only two sorts of people:
i) those who never lie
ii) those who always lie.
You are on your way to Uptown and reach a fork in the road and don’t know which way to go. There is a man there but you have no way of knowing if he is the lying or thruthful sort. What question do you ask in order to discover the way to Uptown?
4. You are invited to the room of a particularly nasty college tutor who has a reputation for taking advantage of poor students like yourself. He challenges you to a game of intellectually challenging riddles and suggests that $10 would be a good wager. What do you do?
5. There’s an inflatable boat in a small swimming pool. You get into it and discover a large slab of wood lying in the bottom. The wood gets in your way and you heave it into the water. Does the water level in the pool rise or fall?
6. A group of college students was given old-fashioned barometers (the sort that has a long tube containing mercury and a scale in cm or inches) and told to go to the tallest building in town (telecom tower with fast lift) and use their barometer to measure its height. What would you have done in their place?
7. How do you know if there have been elephants in your fridge?
8. Why do fridges have lights?
9. Why don’t deep freezes have lights?
10 What is black and deadly?
Answers
1. His son’s.
2. Answer (in outline)
Call the balls a, b, c, d and e
i) Put a&b in one pan and c&d in the other.
If pans balance then e is the odd ball.
ii) If first pan falls, replace a by e (first pan) and swap b and c between pans. If first pan falls on second weighing then d is odd. If it rises than either b or c is odd.
Weigh b against e to find odd ball and determine whether it is under or overweight.
3. You point to one of the forks and say: “If I were to ask you ‘Is this the way to Uptown?’ what would you say?”
4. You agree on condition:
a) His wager is twice yours (to allow for his superior intellectual powers).
b) You ask the first riddle.
c) The base wager be increased from $10 to $100.
The pompous ass will almost certainly agree. You place $100 on the table and hit off with a nonsense riddle such as:
“What has 27 wings, 3 wheels and flies?
After a few pathetic attempts he gives up and demands to know the answer. You say you don’t know and demand the balance of $100 which he now owes you.
5. Archimedes tells us that a floating object displaces its own weight of water and a sunken object displaces its own volume. Therefore, the water level falls if the wood sinks (is denser than water) and stays the same if it floats.
6. The students tried a variety of techniques:
a) One group measured the barometric pressure at the top and bottom of the tower and used the difference to calculate the height. They achieved an accuracy of + 15 metres.
b) A second group threw their barometers from the top of the tower and timed the descent. They achieved an accuracy of + 10 metres but struck a passing pedestrian and were charged with grievous bodily harm.
c) A third group ascended the tower by the fire stairs and used the calibrated rule on their barometers to measure the height, step by step. They achieved an accuracy of + 5 metres.
d) One student went to the desk at the bottom of the tower and said to the employee sitting there. “ I have a barometer that is worth $100. I’ll give it to you if you’ll tell me the height of the tower. She achieved 100% accuracy.
7. You see their footprints in the butter.
8. Elephants are scared of the dark.
9. They are too cold for elephants.
10 A crow with a Kalashnikov
