A man repays a loan of Rs.3250 by paying Rs.20 in the first month and then increases the payment by Rs.15 every month.How long will it take him to clear the loan?

Question

$\begin{array}{1 1}(A) \; \text{12 months}\\(B)\;\text{24 months} \\(C)\;\text{20 months} \\(D)\;\text{15 months} \end{array}$