The interest charged on a loan is Rs.P per every 2500 per month for the first 3 months and Rs.q per every 5000 per month for the subsequent months. How much is the interest charged during the first one and a half year on a loan of Rs.10000?

Hi 2500 per month for first 3 months so when principal is 10,000 interest will be 4P per month now for 3 months interest will be 12P and now remaining 15 months we will pay 2Q as it is said Q for every 5000 so 2Q will be interest for 10000 So total interest becomes 12P+30Q