- Letx¼the time it takes Mary to make the costume and 2x¼the time
it takes Sam to make the costume.
6
x
þ
6
2 x
¼1 LCD¼ 2 x
2 x
6
x
þ 2 x
6
2 x
¼ 2 x 1
12 þ 6 ¼ 2 x
18 ¼ 2 x
18
2
¼
21 x
21
9 hours¼x
- Letx¼the time it takes both people to seed the field.
1
8
þ
1
8
xþ
1
6
x¼1 LCD¼ 24
243
1
1
81
þ
243
1
x
81
þ
244
1
x
61
¼ 24 1
3 þ 3 xþ 4 x¼ 24
3 þ 7 x¼ 24
3 3 þ 7 x¼ 24 3
7 x¼ 21
x¼3 hours
Since the man has already worked an hour before his daughter
started, it will take 1þ 3 ¼4 hours to complete the job.
LESSON 17 Solving Work Problems 193