Math Word Problems Demystified - A Self Teaching Guide

3. Sarah can complete a project in 90 minutes and her sister Betty can
   complete it in 120 minutes. If they both work on the project at the
   same time, how long will it take them to complete the project?


4. One pipe can empty a tank in 45 minutes while a second pipe can
   empty it in 60 minutes. If both pipes are opened at the same time,
   how long will it take to drain the tank?


5. One faucet can fill a large tub in 32 minutes while another faucet can
   fill the tub in 48 minutes. How long will it take to fill the tub if both
   faucets are opened at the same time?


6. A pipe can fill a tank in 120 minutes while the drain can drain it in
   150 minutes. If the drain is left open and the fill pipe is turned on,
   how long will it take to fill the tub?


7. George can complete a project in 75 minutes, and if George and
   Walter both work on the project, they can complete it in 45 minutes.
   How long will it take Walter to complete the project by himself?


8. Pipe A can fill a tank in 60 minutes, Pipe B can fill it in 80 minutes,
   and Pipe C can fill it in 90 minutes. If all three pipes are opened at the
   same time, how long will it take to fill the tank?


9. Mary can make a costume twice as fast as Sam can. If they both
   work together, they can make it in 6 hours. How long will it take
   Mary to make the costume if she works alone?


10. A man can seed a large field in 8 hours. His daughter can do the job
    in 6 hours. If she starts an hour after her father, how long will it take
    to seed the field?

SOLUTIONS:

1. Letx¼the time it takes if both people work together.

1

9

xþ

1

6

x¼1 LCD¼ 18

182

1



x

91

þ

183

1



x

61

¼ 18  1

2 xþ 3 x¼ 18

5 x¼ 18

LESSON 17 Solving Work Problems 189