Question : A person invested Rs. 12,000 on simple interest for 7 years to obtain a total amount of Rs. 20,400 on a certain annual rate of interest. What was the rate of interest to obtain the above amount?

Question : Sudeep invested $\frac{1}{8}$th of a certain sum at 5% p.a. for two years and $\frac{3}{5}$th of the sum at 6% p.a. for two years and the remaining at 10% p.a. for two years. If the total interest received is INR 1,674, then the total sum invested is:

Question : A person invested a sum of INR 10,500 at $x$% per annum at simple interest and a sum of INR 13,500 at $(x + 2)$% p.a. at simple interest. If the total interest earned on both investments for 3 years is INR 7,650, then the rate of interest on the first investment is:

Question : A sum amounts to INR 7,656 in 4 years and to INR 8,120 in 5 years at a certain simple interest rate percent per annum. The rate of interest is:

Question : Ramesh borrowed INR 15,000 at a certain rate of simple interest from a bank. He repaid (the principal but not interest) INR 6,000 after 5 years, and after 5 more years he paid  INR 18,600 and settled his account. Find the rate of simple interest per annum.