Math Word Problems Demystified - A Self Teaching Guide

51 x

5

¼

18

5

x¼ 3 :6 hours

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

1

12

xþ

1

15

x¼1 LCD¼ 60

605

1



x

121

þ

604

1



x

151

¼ 60  1

5 xþ 4 x¼ 60

9 x¼ 60

9 x

9

¼

60

9

x¼ 6

2

3

or 6:67 hours

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

1

90

xþ

1

120

x¼1 LCD¼ 360

3604

1



x

901

þ

3603

1



x

1201

¼ 360  1

4 xþ 3 x¼ 360

7 x¼ 360

71 x

7

¼

360

7

x¼ 51

3

7

or 51:43 hours

190 LESSON 17 Solving Work Problems