# Problems from Another Time

Individual problems from throughout mathematics history, as well as articles that include problem sets for students.

A square walled city measures 10 li on each side. At the center of each side is a gate. Two persons start walking from the center of the city.
If in a circle ABDC, circumscribe an equilateral triangle ABC; the straight line AD is equal to the sum of the two straight lines BD and DC: required a demonstration.
A cat sitting on a wall 4 cubits high saw a rat prowling 8 cubits from the foot of the wall;
The authors recount the 'great tale' of Napier's and Burgi's parallel development of logarithms and urge you to use it in class.
A lady being asked how old she was at the time of her marriage replied that the age of her oldest son was 13; that he was born 2 years after her marriage...
A square circumscribed about a given circle is double in area to a square inscribed in the same circle. True of false? Prove your answer.
Given a guest on horseback rides 300 li in a day. The guest leaves his clothes behind. The host discovers them after 1/3 day, and he starts out with the clothes.
How a translation of Peano's counterexample to the 'theorem' that a zero Wronskian implies linear dependence can help your differential equations students
There is a log 18 feet long, the diameter of the extremities being 1 ft and 2.6 ft respectively...
A bridge is built across a river in 6 months by 45 men. It is washed away by the current. Required the number of workmen sufficient to build another of twice as much worth in 4 months.