#54 Pyramid of possibilities
In the ancient land of Aztekia, people are proud of their historic ziggurat. In it, each block bears a different number that is equal to the product of the two whole numbers on which it rests. Given the two numbers shown, can you complete the monument? Bear in mind that no two numbers are the same on these ziggurats.
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#53 Paintings by numbers
Solution
The neighbouring rooms of room 5, for example, must include rooms 4 and 6, and in general the neighbours of any odd numbered room must be even numbers, while even numbers must have odd neighbours. We can think of the gallery as a mini chessboard, with odds on white squares and evens on black squares. Since there are five odds and four evens, the corners and the centre square must be the five odd numbers. Where can room 1 be? It can鈥檛 be bottom left, as the two rows above it must add to more than 200. By trying to trace paths 1-2-3鈥� and so on, you can also quickly rule 1 out from bottom right, top right and centre. The only path that works is:
Quick quiz #46
1 Laurasia + Gondwana = ?
2 Barbara McClintock won the 1983 Nobel prize in physiology or medicine for discoveries in genetics made by studying which plant?
3 What 1962 book by Rachel Carson about pesticide harms is credited with starting the modern environmental movement?
4 To make a Josephson junction, what special sort of material do you need?
5 Where is the sea known as Kraken Mare?
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Quick quiz #46
Answers
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2 Maize
3 Silent Spring
4 Superconductors. Fix it up right, and current will flow indefinitely across the junction with no voltage applied
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