How to Answer Work Problems on the ASVAB

By Rod Powers

You will encounter work problems on the ASVAB. These problems involve two or more people or things working together. You’re expected to figure out how long they’ll take to complete a task together.

Patrick can build a wall in five hours. Dennis can build the same wall in seven hours. How long will they take to build the wall together?

You can use a general formula to solve such work problems. It’s


where a is the time the first person or thing takes to do the job and b is the time it takes the second person or thing takes to do the job.

Patrick needs five hours to build the wall, and Dennis seven hours. Plugging the data into the work formula gets you the following:


It will take them


hours to build the wall together.

Wasn’t that fun? Give another one a try.

One hose can fill an aboveground pool in three hours. Another hose will fill it in six hours. How long will filling the pool take using both hoses?

Just plug the numbers into your handy-dandy work equation:


It will take two hours to fill the pool when using both hoses.