Q101
ArithmeticTime & Work, Pipes & Cisterns
A and B can do a work in 12 and 15 days respectively. They started the work together but A left after 4 days due to illness. The remaining work was finished by B in:
- a.5 days
- b.6 days
- c.10 days
- d.12 days
Answer: (B) 6 days
Together they do $\frac{1}{12} + \frac{1}{15} = \frac{3}{20}$ a day, so in 4 days they finish $\frac{3}{5}$ of the work. B alone does the remaining $\frac{2}{5}$ in $\frac{2}{5} \times 15 = 6$ days. 10 days would be B's time for $\frac{2}{3}$ of the work.