Q29
ArithmeticTime & Work, Pipes & Cisterns
Ramesh and Rahman can do a work in 20 and 25 days respectively. After doing collectively 10 days of work, they leave the work due to illness and Suresh completes the rest of the work in 3 days. How many days Suresh alone can take to complete the whole work?
- a.30 days
- b.32 days
- c.28 days
- d.29 days
Answer: (A) 30 days
Together Ramesh and Rahman do $\frac{1}{20} + \frac{1}{25} = \frac{9}{100}$ of the work a day, so in 10 days they finish $\frac{90}{100}$. Suresh does the remaining $\frac{1}{10}$ in 3 days, so he alone needs 30 days. The other options do not match $\frac{1}{10}$ in 3 days.