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?
40/9days
39/5days
51/9days
None of these
Explanation:
As one hour work = 1/8. Bs one hour work = 1/10. (A+B)s one hour work
= 1/8+1/10 = 9/40. Both A & B can finish the work in 40/9 days
As one hour work = 1/8. Bs one hour work = 1/10. (A+B)s one hour work
= 1/8+1/10 = 9/40. Both A & B can finish the work in 40/9 days