nitin borrowed some money at the rate of 6 % p . a . for the first 3 years , 9 % p . a . for the next 5 years and 13 % p . a . for the period beyond 8 years . if the total interest paid by him at the end of 11 years is rs . 8160 , how much money did he borrow ?
let the sum be rs . x . then , [ ( x * 6 * 3 ) / 100 ] + [ ( x * 9 * 5 ) / 100 ] + [ ( x * 13 * 3 ) / 100 ] = 8160 18 x + 45 x + 39 x = ( 8160 * 100 ) 102 x = 816000 = > x = 8000 . answer : a
divide(multiply(8160, const_100), add(add(multiply(6, 3), multiply(9, 5)), multiply(13, 3)))