31 x
3
¼
30
3
x¼10 hours
Hence it will take 10 hours to fill the pool.
EVALUATION: Check the equation:
x
6
x
15
¼ 1
x¼ 10
10
6
10
15
¼ 1
1 : 67 0 : 67 ¼ 1
1 ¼ 1
EXAMPLE:Mary can do a job in 80 minutes. Working with Jane, both can
do the job in 30 minutes. How long will it take Jane to do the job alone?
SOLUTION:
GOAL: You are being asked to find the time in minutes it takes for Jane to
complete the job alone.
STRATEGY: Letx¼the time it takes Jane to complete the job.
Rate Time ¼ Amount of work done
Mary^1
80
30 30
80
Jane^1
x
30 30
x
The equation is
30
80
þ
30
x
¼ 1
LESSON 17 Solving Work Problems 187