The city of Königsberg, now Kaliningrad, is located on the two shores of the Pregel River. In the early 1700s seven bridges connected two...

A magic square is a combination of numbers arranged in a square such that the sum of each row, column and both the corner diagonals is...

Example 1. Annemarie is cutting out coupons for her favorite restaurant, Adelinas Ballhaus, from the newspaper. Coupon denominations are...