A person works on a project and completes 5/8 of the job in 10 days. At this rate, how many more days will he it take to finish the job?

A person completes 5/8 part of the project in 10 days.
A person completes the project in 10/5/8 days.
A person completes the project in 10 x 8 /5 days.
A person completes the project in 2 x 8 days.
A person completes the project in 16 days.