On retirement Kamal gets Rs 3200000 as gratuity. He invested this amount in two banks in such a way that he earns Rs. 23000 every month as interest. If the annual interest rate of the banks are 9% and 8% respectively. What amount is invested in the bank with higher rate of interest?

Let x be the amount invested at 9%. Then (3200000-x) is invested at 8%. Annual interest from first bank: 0.09x. Annual interest from second bank: 0.08(3200000-x). Total annual interest: 23000×12 = 276000. So 0.09x + 0.08(3200000-x) = 276000. Solving: 0.09x + 256000 - 0.08x = 276000, so 0.01x = 20000, giving x = 2000000. This is the amount at 9% (higher rate), so the answer is correct.