The rate of simple interest for first 3 year is 6%, for next 4 years it is 7% and the period beyond 7 years it is 7.5% per annum. If a man invest ₹9400 for 11 years, find the simple interest earned by him?

₹7144

Total S.I. for first 3 years   = 6% × 3    = 18%

Total S.I. for next 4 years  = 7% × 4    = 28%

Total S.I. for next 4 years  = 7.5% × 4 = 30%

Total S.I. for 11 years = (18 + 28 + 30)% = 76%

S.I. for 11 years = 9400 × 76% = 7144/-