If 4/5 of an estate be worth Rs. 16800, then the value of 3/7 of it is -

Answer: Option B

$$\begin{array}{rl}& \frac{4}{5}\text{ of an estate = 16800}\\ & \text{1 of an estate = 16800}\times \frac{5}{4}\\ & =21000\\ & \frac{3}{7}\text{ of an estate = 21000}\times \frac{3}{7}\\ & =9000\end{array}$$