Worker A takes 8 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) 40 days  B) 40/9 days  C) 39/9 days  D) 30/9 days  E) 60/9 days
B   40/9 days   A's one hour work = 1/8.   B's one hour work = 1/10.   (A+B)'s one hour work = 1/8+1/10 = 9/40.   40/9 daysoth A &amp; 40/9 days can finish the work in 40/9 days
<result>B</result>
Worker A takes 8 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?