Worker A takes 5 hours to do a job. Worker B takes 15 hours to do the same job. How long it take both A & B, working together but independently, to do the same job?
Select the correct option:
A) 15/4
B) 40/9
C) 50/9
D) 60/9
E) 80/9
one day work of 15/4 = 1/5   one day work of B = 1/15   so one day work of 15/4 and B together = 1/5 + 1/15 = 4/15   so total days required = 15/4   15/4NSWER:15/4
<result>A</result>
Worker A takes 5 hours to do a job. Worker B takes 15 hours to do the same job. How long it take both A & B, working together but independently, to do the same job?