C#

if (TotalMark >= 80)
    return "HD";
if (TotalMark < 40)
    return "F";
if ((LabsMarks + Assignment1 + Assignment2) >= 25 && Final >= 25)
{   //passed
    if (TotalMark < 50)
        return "MF";
    if (TotalMark < 60)
        return "P";
    if (TotalMark < 70)
        return "C";
    if (TotalMark < 80)
        return "D";
}
else
{
    return "MF";
}

if (TotalMark < 50) //false, fall through
    return "MF";
if (TotalMark < 60) //false, fall through
    return "P";
if (TotalMark < 70) //false, fall through
    return "C";
if (TotalMark < 80) //true, return "D"
    return "D";

William Winner wrote:

By the way, if they passed, then there's no way they scored less than 50, since 50 is the minimum required to pass. So, you'll never get to the return "MF" under if (TotalMark < 50).

public readonly string Grade()

public string Grade
{
    get
    {
        //put your code here
    }
}

int totalMark = LabsMark + Assignment1 + Assignment2 + Final;

//Test if less than 40
if (totalMark < 40)
{
  return "F";
}
else if (!Passed())
{
  //if you get here, then they scored over 40
  //if they scored less than 50, then they didn't pass anyway
  //so you don't need to check that case
  return "MF";
}
else if (totalMark < 60)
{
  return "P";
}
// more else if statements to test the rest

if (tmp == null)
{
   throw new NullReferenceException();
}

CustomObject tmp = StupidOperations.MakeSureItIsntNull( new CustomObject() );