mr . karan borrowed a certain amount at 6 % per annum simple interest for 9 years . after 9 years , he returned rs . 8210 / - . find out the amount that he borrowed .
"explanation : let us assume mr . karan borrowed amount is rs . a . ( the principal ) by formula of simple interest , s . i . = prt / 100 where p = the principal , r = rate of interest as a % , t = time in years s . i . = ( p * 6 * 9 ) / 100 = 54 p / 100 amount = principal + s . i . 8210 = p + ( 54 p / 100 ) 8210 = ( 100 p + 54 p ) / 100 8210 = 154 p / 100 p = ( 8210 * 100 ) / 154 = rs . 5331.169 answer : a"
divide(8210, add(const_1, divide(multiply(6, 9), const_100)))