#112 A muse in barrels
In Sweden, at the Barrel Olaf storage yard, a small, cylindrical wooden barrel with a diameter of 20 centimetres has been placed against a straight windbreak inclined at 60 degrees to the horizontal. Two more, larger barrels have been pushed up against it so that each touches any neighbours and the windbreak (as shown).
What is the diameter of the third barrel?
Answers next week
#111 Eclair-voyance
Solution
Amy had the 6 of spades and Tom had the 5. When Tom first says he doesn鈥檛 know whether he will win, he can鈥檛 have either the 2 or the 10, or he would know.
Amy picks up on this, so 鈥淪ame goes for me鈥� implies that she doesn鈥檛 have the 2 or 10, but also that she doesn鈥檛 have the 3 or 9, for then she would know whether she had won or lost.
Tom鈥檚 admission that he still doesn鈥檛 know means he has neither the 3 or 9, nor the 4 or 8. So he must have the 5, 6 or 7.
Amy still not knowing means she has the 6, the only card for which the outcome would still be unsure. Realising this, Tom admits defeat, because he has the 5.
Quick quiz #100
1 The production of fruit without fertilisation, thereby making them seedless, is known as what?
2 What does ENIAC stand for?
3 Roughly how long did it take NASA鈥檚 New Horizons probe to reach Pluto?
4 How many geologic periods made up the Palaeozoic era?
5 Which element has an atomic number of 100?
Answers
1 Parthenocarpy
2 Electronic Numerical Integrator and Computer. It was the first general-purpose computer
4 Nine-and-a-half years.
3 Six: the Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian periods
5 Fermium