On a certain principal the compound interest compounded annually for the second year at (x)% per annum is 110% of the compound interest for the first year. The difference in the compound interest for the second year and simple interest for the fifth year on the same principal is Rs.12. The principal is-

Let principal = P, rate = x%. CI for 1st year = P × x/100. CI for 2nd year = P(1 + x/100) × x/100 = (P × x/100)(1 + x/100). Given: 2nd year CI is 110% of 1st year CI, so (1 + x/100) = 1.10, giving x = 10%. SI for 5 years = P × 10 × 5/100 = P/2. CI for 5 years = P(1.1^5 - 1) ≈ 0.61051P. Difference = 0.61051P - 0.5P = 0.11051P ≈ Rs. 12. So P ≈ Rs. 108.6. Wait, let me reconsider. The difference between CI for 2nd year and SI for 5th year: CI(2nd year) = P × 0.1 × 1.1 = 0.11P. SI for 5th year alone = P × 0.1 = 0.1P. Difference = 0.11P - 0.1P = 0.01P = 12. So P = Rs. 1200.