the difference between simple interest and compound interest of a certain sum of money at 20 % per annum for 2 years is $ 48 . then the sum is
"20 % of ( year 1 interest ) = 20 % of ( 20 % of principal ) = 48 principal = $ 1200 answer ( c )"
subtract(subtract(multiply(power(add(divide(divide(2, const_2), const_100), const_1), const_2), 20), 20), divide(multiply(20, 2), const_100))