A man borrowed Rs.18800 at the rate of 6% per annum for the first three years, at the rate of 7% per annum for the next four years and at the rate of 7.5% per annum for the period beyond of next seven years. If he borrowed that money for 11 years then find the total simple interest earned by him.

Rs.14288

Total rate = (6% x 3) + (7% x 4) + (7.5% x 4) = 76%

Simple Interest = \(\frac{18800\;×\;76}{100}\)

                      = ₨.14288