Question

Nancy can do a typing job in 8 hours. When Carole helps her, they can do the job together in 5 hours. How many hours would it take Carole to do the job alone?

Answer 1

It would be 13 hours and 20 minutes

Answer 2

`13(1)/(3) hours`

Explanation:

Let the total work done by nancy = 1

Total time taken by Nancy to complete a job = 8 hours

Total work done by Nancy in 1 hour =
`(1)/(8)`

Total work done together by Carole and Nacy in 5 hours = 1

Total work done by together Carole and Nacy in 1 hours =
`(1)/(5)`

Now, total job done by Carole alone in 1 hour is:

= Total work done by Carole and Nacy in 1 hours - Total work done together by Nancy in 1 hour

=
`(1)/(5) -(1)/(8)`

=
`(8 - 5)/(40)`

=
`(3)/(40)`

Total work done by Carole in 1 hour = 3/40

Number of hours required by Carole to complete the job alone = 40/3 hours.

Number of hours taken by Carole to do the job alone = 40/3 =
`13(1)/(3) hours`