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? Choose one:
A) 6 days
B) 40 days
C) 5 days
D) 12 days
E) 40/9 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.   Ans: 40/9 days
<result>E</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?