#184 Cipher sum
Set by Rob Eastaway
The sum shown below appears to be nothing out of the ordinary. The figures add up correctly as you would expect. But it has a rather unusual property. This is a cipher sum. Each of the digits represents a different digit, with the same digit always representing the same alternative digit.
The sum that it represents also adds up correctly. Can you find it?
26374
+ 46462
72836
Solution next week
#183 Animal rights
Solution
The books are arranged in this order:
The catch (that most people miss) is that the first page in any book is on the right as you look at the spine of the book, while the last page is on the left. If you need convincing, take a book off your shelf, bookmark the first page and put it back on the shelf.
Quick quiz #168
1 In mathematics, the numbers 8, 17, 32, 54, 57 and 100 are the first six of which type of number?
2 In what year did Howard Carter鈥檚 archaeological expedition find the entrance to Tutankhamun鈥檚 tomb?
3 Which of these elements is an actinide: thulium, fermium or samarium?
4 Who was the inventor of the mass spectrograph?
5 How many living species of the Panthera genus are there?
Quick quiz #168
Answers
1 Leyland numbers, which can be expressed as xy + yx where x and y are integers greater than 1
2 1922
3 Fermium
4 Francis Aston
5 Five