Volume 9
, Issue 1


If you went to Stockholm today, you would find in the middle of the city an "oval-shaped" pool about 200 meters long with fountains and a translucent base. Under this pool is a self-service restaurant with sunlight filtering through the pool and surrounded by shops.

In how many different ways can 4 be expressed as the sum of positive integers?

Two of the interesting problems related to chess are the number of queens needed to dominate a chess board and how few squares can be attacked by a given number of queens.

With regard to the case in "Research Corner" concerning number which can be written as the sum of three squares and four squares, all numbers of the form $m^{2n}(8k+6)$ can only be written as the sum of at least three square numbers

This is a game which was invented by Piet Hein, although it was rediscovered in 1948 by John Nash in America.

"Number, the language of science" by T. Dantzig

J201 Find the last digit of $7^{1001}$.

J191 A yacht starts from a point $A$, one mile due East of a buoy $O$, and tacks up to the buoy as indicated in the diagram.