The cost of 4 dozen papers is Rs. 24. The cost of 1 score of papers (in rupees) is ?

Answer: Option C

1 score of papers = 20 papers
Cost of 4 dozen papers = Rs.24
Cost of 20 papers
$$\begin{array}{rl}& =\frac{24}{4\times 12}\times 20\\ & =\text{Rs}\text{.10}\end{array}$$