Ram deposited a certain sum of money in a company at 12% per annum simple interest for 4 years and deposited equal amounts in fixed deposit in a bank for 5 years at 15% per annum simple interest. If the difference in the interest from two sources is Rs. 1350 then the sum deposited in each case is = ?

Explanation:-

Difference between their rates he gained from both boys
$$\eqalign{ & \Rightarrow (15 \times 5)\% - (12 \times 4)\% \cr & \Rightarrow 75\% - 48\% \cr & \Rightarrow 27\% = 1350{\text{ }}({\text{given)}} \cr & \Rightarrow 100\% = {\text{Rs}}{\text{. 5000}} \cr}$$