CodingBat > roundSum

For this problem, we'll round an int value up to the next multiple of 10 if its rightmost digit is 5 or more, so 15 rounds up to 20. Alternately, round down to the previous multiple of 10 if its rightmost digit is less than 5, so 12 rounds down to 10. Given 3 ints, a b c, return the sum of their rounded values. To avoid code repetition, write a separate helper "public int round10(int num) {" and call it 3 times. Write the helper entirely below and at the same indent level as roundSum().

roundSum(16, 17, 18) → 60
roundSum(12, 13, 14) → 30
roundSum(6, 4, 4) → 10

Solution ::

 public int roundSum(int a, int b, int c) {
    return round10(a) + round10(b) + round10(c);
 }
 public int round10(int num) {
    int remainder = num % 10;
    num -= remainder;
    if (remainder >= 5) {
       num += 10;
    }
    return num;
 }