Given: The simple interest on a sum of money for one year is Rs. 260 and The compound interest on the same sum for two years is Rs. 540.80 Formula Used:SI=100P×r×t​CI=P((1+100r​)t−1) Where p is the sum, r is rate and t is the time in years. Calculation: According to the question ⇒ 260=100p×r​ ⇒ 540.80=p((1+100r​)2−1) Dividing the two equations we get, ⇒ 540.80260​=(1+100r​)2−1100r​​ ⇒ 5225​=(100r​)2+1002r​100r​​ ⇒ 1001​+2=2552​⇒r=25200​∴ The rate percent per annum is 8.