Worker A takes 8 hours to do a job. Worker B takes 10 hour to do the same job. How long should it take both A and B, working together but independently, to do the same job?
সমাধান
সঠিক উত্তর: Option A
working together, they can do 1/10+1/8=9/40
they can do the whole job in: 40/9 days=4(4/9) days
