What rate present does a man get for his money when in discounting a bill due 10 months hence he deducts 10% of the amount of the bill ?

Answer: Option C

Let amount of the bill = Rs. 100. Money deducted = Rs. 10
Money received by the holder of the bill = Rs. (110 - 10) = Rs. 90
∴ S.I. on Rs. 90 for 10 months = Rs. 10
$$\begin{array}{rl}& \therefore \text{Rate}=\left(\frac{100\times 10}{90\times \frac{10}{12}}\right)\%\\ & =13\frac{1}{3}\%\end{array}$$