The rate of Glenn in finishing a job would be equivalent to:
Rate (G) = 1
job / 20 minutes
While the rate of Veronika is:
Rate (V) = 1
job / x---> x is the unknown
Where 1 job for Glenn means completely cleaning his room while 1 job for Veronika means pulling out everything. Therefore the equation to use would be:
1 / 20 – 1 /
x = 1 / 60
The rate of
Veronika is subtracted from the rate of Glenn since Veronika is slowing Glenn
down. Solving for x:
Multiply both
sides by 60 x
(1 / 20 – 1 /
x = 1 / 60) * 60 x
3 x – 60 = x
2 x = 60
x = 30
Therefore it
takes 30 minutes for Veronika to pull everything out.
