Anamika invests a sum of ₹ 5,000 which amounts to ₹ 6,200 in 7 years. Find the interest earned.
Mr Kumar invested a sum of Rs. 15000 at 6% p.a. simple interest and another amount at 8% p.a. simple interest. The total interest earned at the end of one year on the total amount invested becomes 7% p.a. Find the total amount invested.