The true discount on Rs. 2562 due 4 months hence is Rs. 122. The rate percent is:

Answer: Option C

$$\begin{array}{rl}& \text{P}\text{.W}\text{.}=Rs.\left(2562-122\right)\\ & =Rs.2440\\ & \therefore \text{S}\text{.I}\text{.}\text{on}\text{Rs}\text{.}\text{2440}\text{for}\text{4}\text{months}\text{is}\text{Rs}\text{.}\text{122}\text{.}\\ & \therefore \text{Rate}=\left[\frac{100\times 122}{2440\times \frac{1}{3}}\right]\%=15\%\end{array}$$