A,B worker are doing a job. Worker A takes 8 hours to do a job. B takes 10 hours to do a job. How long should it take both A and B, working together to do same job. Choices.
A) 4 4/9
B) 3 3/9
C) 3 2/9
D) 5 2/9
E) 6 4/9
In this type of questions, first we need to calculate 1 hours work, then their collective work as,   4 4/9's 1 hour work is 1/8   B's 1 hour work is 1/10   (4 4/9+B)'s 1 hour work = 1/8 + 1/10   = 9/40   So both will finish the work in 40/9 hours   = 4 4/9   4 4/9NSWER 4 4/9
<result>A</result>
A,B worker are doing a job. Worker A takes 8 hours to do a job. B takes 10 hours to do a job. How long should it take both A and B, working together to do same job.