Answer:
The amount of work completed by Jing in 1 hour is 0.075 which is option A
Explanation:
Melissa & Jing can complete the work in 5 hours
This means that the amount of work completed by Melissa & Jing working together in 1 hour is (1÷5) = 0.2
Melissa will do the job in 8 hours, which means that the amount of job completed by Melissa working alone in 1 hour is (1÷8) = 0.125
The amount of work completed by Jing when he works alone in 1 hour will be the difference of amount of work completed by both of them in 1 hour with the amount completed by only Melissa in 1 hour.
There Amount of work completed by Jing in an hour = 0.2 - 0.125 = 0.075