Two workers, a trainer and a trainee, working together can do a job in 3 hours. The trainer is 3 times faster than the trainee to complete the same job. How long will it take the trainee to finish the same job?

4 hours

Step-by-step explanation:

Ratio of working together

Job : number of hours

1 : 3 = 1/3

Trainer

Job : number of hours

1 : x = 1/x

Trainee

Job : number of hours

1 : 3x = 1/3x

1/x + 1/3x = 1/3

Multiply through by 3x

3x(1/x) + 3x(1/3x) = 3x(1/3)

3 + 1 = x

4 = x

x = 4 hours

It takes the trainee 4 hours to finish the job

multiple all that

step-by-step explanation:

27×17