# Convergence articles

Displaying 601 - 610 of 656

An elementary introduction to Euler squares and how they can be used in teacher training

What is the sum of the reciprocals of the triangular numbers?
A cliff with a tower on its edge is observed from a boat at sea; find the height of the cliff and the tower.

Author Keith Devlin argues that the impact of the Pisan merchant and his Arabic numbers on medieval Europe was even greater than previously thought.

My age is a number consisting of two digits, 1/2 of this number is a mean proportional between these two digits, and two years hence, my age will be a third proportional to the same two digits, directly as they stand in my present age.
Two circles of radii 25 feet intersect so that the distance between their centers is 30 feet. What is the length of the side of the largest square inscribable within their intersecting arcs?
This is the title page of the first textbook in the calculus of variations, Leonhard Euler's Method of Finding Curved Lines that Show some Property of Maximum or Minimum. It was published in 1744.
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?
Two travelers, starting at the same time from the same point, travel in opposite directions round a circular railway.
A leech invited a slug for a lunch a leuca away.