Algorithms, Graphs, and Computers (Enhanced Edition‪)‬

In elementary courses in algebra, we study how to convert word problems
of various types into problems involving the solution of algebraic
equations. Particular favorites are "rate" problems. In these classroom
conundrums, people are always busily traversing streets, streams, rivers,
highways, byways, and airways by means of a bizarre assortment of transportation
devices ranging from jet planes, automobiles, and canoes to bicycles,
camels, and horses, and even occasionally by foot. It is usually required
to determine a time, a speed or a distance. Sometimes, the rate and route
are given and it is the time that is desired; in other cases the time elapsed
and the route are the initial data and it is the speed that is missing; in still
other situations rate and time are the given information and it is the overall
distance that is required.