Worker A takes 8 hours to do a job. Worker B takes 10 hours to do the same Job.How long should it take both A and B, working together but independently, to do the same job?  Options
A) 20/6 days  B) 15/4 days  C) 40/9 days  D) 40/3 days  E) 45/7 days
A’s 1 hour's work = 1/8   B's 1 hour's work = 1/10   (A + B)'s 1 hour's work = (1/8) +(1/10)=9/40   Both A and B will finish the work in 40/9 days   Answer is 40/9 days.
<result>C</result>
Worker A takes 8 hours to do a job. Worker B takes 10 hours to do the same Job.How long should it take both A and B, working together but independently, to do the same job?