A computer expert can do a job in 6 hours.
His secretary can do the same job in 7 hrs.
After the expert works on the job foe 2 hours,
his secretary takes over and complete the job.
How many hrs did it take her to complete the job?
The secretary can do the job in 7 hours.
In one hour, she completes of the job.
In hours, she completes of the job.
The expert has already completed of the job.
The secretary will complete the other of the job.
There is our equation: .
It took her hours to complete the job.