Work Problems

Example 1

Ernie can plow a field alone in four hours. It takes Sid five hours to plow the same field alone. If they work together (and each has a plow), how long will it take to plow the field?

First, circle what you must find— how long …together. Work problems of this nature may be solved by using the following equation.

equation

Therefore,

equation

Finding a common denominator

equation

Cross multiplying

equation

Therefore, it will take them equation hours working together.