Q40
ArithmeticTime & Work, Pipes & Cisterns
A and B can do a work in 8 days, B and C can do the same work in 12 days. A, B and C together can finish it in 6 days. A and C together will do it in
- a.4 days
- b.6 days
- c.12 days
- d.8 days
Answer: (D) 8 days
A's daily work = $\frac{1}{6} - \frac{1}{12} = \frac{1}{12}$ and C's = $\frac{1}{6} - \frac{1}{8} = \frac{1}{24}$. Together A and C do $\frac{3}{24} = \frac{1}{8}$ a day, so they need 8 days. 6 days is the time for all three together.