A man bought a number of sheep for $225; 10 of them having died, he sold 4/5 of the remainder for the same cost and received $150 for them. How many did he buy?

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

A barrel has various holes in it. The fist hole empties the barrel in three days...

Suppose a man had put out one cent at compound interest in 1620, what would have been the amount in 1824, allowing it to double once in 12 years?

A circle, a square and an equilateral triangle all have the same perimeter equal to 1 meter. Compare their areas.

Determine the different values of x, when a certain function hits a minimum.

Given a door and a measuring rod of unknown dimensions, the rod is used to measure the door.

Gun metal of a certain grade is composed of 16% tin and 84% copper. How much tin must be added to 410 lbs. of this gun metal to make a composition of 18% tin?

Now there are six-headed four legged animals and four-headed two-legged birds. Find the total number of animals and birds.

The authors recount the 'great tale' of Napier's and Burgi's parallel development of logarithms and urge you to use it in class.

Now there is a wall 5 feet thick and two rats tunnel from opposite sides.