How to get the correct value by calculating double values....

Hello Sir, I have a method in which i am getting getting wrong datavalues calculated from the function ...here is my code for this task....

 try {
         //DecimalFormat df = new DecimalFormat("#.##");
        double min = 60;
        double cost = 0;
        double quotient = duration / min;
        double rem = duration % min;
        if (rem >= 0) {
            double quotient1 = quotient + 1;
            cost = quotient1 * rateperpulse;
           // df.format(cost);
            System.out.println(cost);
        }

duration is integer type and values like 59,142 etc

here i am getting wrong output for the same duration 59 i am getting wrong cost .. Sir plz help me in this code.Thank you Sir.