GMAT Exam: A Simple Guide To Solving Word Problems - Work

In a typical work problem, you are given the time, call it x, that it will take one person (or device) to do a task, working alone, and the time, call it y, that it will take another person (or device) to do the same task, working alone.

Then the time it will take both of them, working together, is



Example: Working alone, Dylan can paint the walls of a long hallway in 4 hours. Jeremy can paint the walls of the hallway in 3 hours, working alone. How long will it take them, working together, to paint the hallway?

Omitting the units, calculate

.

The time it will take Dylan and Jeremy, working together, to paint the hallway is hours.