A sum of money was invested at a certain rate of simple interest for 2 years. Had it been invested at 1% higher rate, it would have fetched Rs. 24 more interest. The sum of money is ?

More interest paid in 2 years
$$\eqalign{ & {\text{ = 2}} \times {\text{1}} = {\text{2}}\% \cr & {\text{According to the question, }} \cr & {\text{2}}\% {\text{ of sum = Rs}}{\text{. 24}} \cr & {\text{1}}\% {\text{ of sum = Rs}}{\text{.}}\frac{{24}}{2} \cr & {\text{Total sum}} \cr & {\text{ = Rs}}{\text{. }}\frac{{24}}{2} \times 100 \cr & = {\text{Rs}}{\text{. }}1200 \cr} $$