Worker A takes 6 hours to do a job. Worker B takes 10 hours to do the same job. How long it take both A & B, working together but independently, to do the same job?
Choose the correct choice from the following answers.
A) 15/4 days B) 40/9 days C) 39/9 days D) 30/9 days E) 60/9 days
A's one hour work = 1/6.   B's one hour work = 1/10.   (A+B)'s one hour work = 1/6+1/10 = 8/30 = 4/15.   Both 15/4 days &amp; B can finish the work in 15/4 days   15/4 days
<result>A</result>
Worker A takes 6 hours to do a job. Worker B takes 10 hours to do the same job. How long it take both A & B, working together but independently, to do the same job?