Math Word Problems Demystified - A Self Teaching Guide

4. Letx¼the time it will take to fill the tank if both pipes are open at the
   same time.
   1
   45

xþ

1

60

x¼1 LCD¼ 180

1804

1



x

451

þ

1803

1



x

601

¼ 180  1

4 xþ 3 x¼ 180

7 x¼ 180

71 x

71

¼

180

7

x¼ 25

5

7

or 25:71 minutes

5. Letx¼the time it will take to fill the tub if both faucets are open.
   1
   32

xþ

1

48

x¼1 LCD¼ 96

963

1



x

321

þ

962

1



x

481

¼ 96  1

3 xþ 2 x¼ 96

5 x¼ 96

51 x

51

¼

96

5

x¼ 19 :2 minutes

6. Letx¼the time it will take to fill the tank.
   1
   120

x

1

150

x¼1 LCD¼ 600

6005

1



x

1201

6004

1



x

150

¼ 600  1

5 x
 4 x¼ 600

x¼600 minutes

LESSON 17 Solving Work Problems 191