Find the compound interest on ₹8,000 at 12% per annum for 3 years 4 months,…

For 3 complete years, amount = 8000 x 1.12^3 = 11239.424. For the remaining 4 months, simple interest on this amount at 12% per annum is 4%, so final amount is about 11689. Compound interest = 11689 - 8000 = 3689.