The true discount on a bill for Rs. 2520 due 6 months hence at 10% per annum is

Answer: Option D

$$\begin{array}{rl}& F=\text{Rs}\text{.}2520\\ & T=6\text{months}=\frac{1}{2}\text{years}\\ & R=10\%\\ & TD=\frac{FTR}{100+\left(TR\right)}\\ & =\frac{2520\times \frac{1}{2}\times 10}{100+\left(\frac{1}{2}\times 10\right)}\\ & =\frac{1260\times 10}{100+5}\\ & =\frac{12600}{105}\\ & =\frac{2520}{21}\\ & =\text{Rs}\text{.}120\end{array}$$