Worker A takes 5 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 most appropriate option.
A) 20/9 B) 40/9 C) 50/9 D) 60/9 E) 10/3
one day work of A = 1/5   one day work of B = 1/10   so one day work of A and B together = 1/5 + 1/10 = 3/10   so total days required = 10/3   ANSW10/3R:10/3
<result>E</result>
Worker A takes 5 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?