Shivani invested Rs.18000 in two different parts and the interest received at the rate of 8% SI for two years is equal to the interest received at the rate of 10% interest for two years. Find the difference between the Sum invested in 10% and 8%.

Let amounts at 8% and 10% be x and y respectively. Interest equality: x*8*2/100 = y*10*2/100. Simplifying: 16x = 20y, so x/y = 20/16 = 5/4. Also x + y = 18000. Using ratio, if 9 parts = 18000, then 1 part = 2000. Difference |y - x| = |4-5| parts = 2000. The question asks for difference between 10% and 8% investments, which is Rs 2000.