Harpreet borrowed Rs 20000 from her friend at $12\%$ per annum simple interest. She lent it to Alam at the same rate but compounded annually. Find her gain after 2 years.

$\text{In case of Harpreet :}\text{Amount borrowed by Harpreet (P) = Rs. 20000}\text{Rate (r) =}12\%\text{Period (t) = 2 Years}\therefore S.I.=\frac{prt}{100}=\frac{20000\times 12\times 2}{100}=Rs.4800\text{In case of Alam :}\therefore \text{Interest for the 1st year}=\frac{20000\times 12\times 1}{100}=Rs.2400\text{Amount at the end of first year = Rs. 20000}Rs.2400=Rs.22400\text{Interest for the second year = Rs}\frac{22400\times 12\times 1}{100}=Rs.2688\therefore \text{C.I. for 2 years =}Rs.2400+2688=Rs.5088\therefore \text{Amount of gain =}Rs.5088-Rs4800=Rs.288Ans.$