# Problems from Another Time

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

When knowing the sum of their ages along with another equation, determine how old a father and son are.
How a translation of Peano's counterexample to the 'theorem' that a zero Wronskian implies linear dependence can help your differential equations students
Now there are three sisters who leave home together.
A California miner has a spherical ball of gold, 2 inches in diamter, which he wants to exchange for spherical balls 1 inch in diameter. How many of the smaller spheres should he receive?
The sum of two numbers is 10 and their product is 40. What are the numbers?
Discussion of 15th century French manuscript, with translation of its problems, including one with negative solutions
There is a four-sided field whose eastern side measures 35 paces, its western side 45 paces, its southern side 25 paces and its northern side 15 paces. Find the area of this field.
In baking a hemispherical loaf of bread of 10" radius, the crust was everywhere of an equal thickness, and the solidity of the crust was equal to half the solid content of the whole loaf. What were the dimensions of the interior soft part?
Given a triangular piece of land having two sides 10 yards in length and its base 12 yards, what is the largest square that can be constructed within this piece of land so that one of its sides lies along the base of the triangle?
The sum of the two digits of a 2-digit number is 9. If 45 is subtracted from the number, the result will be expressed by the digits in reverse order. Find the number.