For this we can start by calculating the amount that original investment will become after 9 years:Let the initial principal be Pafter 1st year P * 1.06 = 1.06Pafter 2nd year 1.06P * 1.06 = 1.12Pafter 3rd year 1.12P *1.1 = 1.23Pafter 4th year 1.23 P* 1.1  = 1.35Pafter the 5th year 1.35P * 1.1 = 1.485Pafter this for 4 years the interest rates will be 15% so we can use the formula for compound interest calculationsafter 9 years, 1.485P (1.15)^4 = 2.6Pso the amount become 2.6P in 9 years interest gained 2.6P -P = 1.6P 1.6P = 8262P = 5163.75P.S. Do let me know if the answer matches the value in the answer

Can't solve Arjuna deposited certain amount in national bank at 6% p.a. for 2 years. The interest was increased to 10% p.a. after 2 years and to 15% p.a. beyond 5 years on the initial amount. If the interest earned after 9 years is Rs. 8262, then find the deposited amount.