A and B can do a piece of work in 25 days. B alone can do 662/3\% of the same work in 30 days. In how many days can A alone do 415 part of the same work?

Answer: Option A

Solution

Answer: Option A

Solution:

$$\begin{array}{rl}& 66\frac{2}{3}\%\to 30\text{ days}\\ & \frac{2}{3}\to 30\text{ days}\\ & 1\to 45\text{ days}\end{array}$$

$$\begin{array}{rl}& \text{A}=4\text{ unit}\\ & \text{A}=\frac{25\times \frac{4}{15}}{4}\\ & \text{A}=15\text{ days}\end{array}$$