if a lends rs . 2000 to b at 10 % per annum and b lends the same sum to c at 11.5 % per annum then the gain of b in a period of 3 years is ?
"( 2000 * 1.5 * 3 ) / 100 = > 90 answer : a"
subtract(divide(multiply(multiply(2000, 11.5), 3), const_100), divide(multiply(multiply(2000, 10), 3), const_100))