JuniorTheoryCommon

What does the program print (lines separated by spaces)?

int score = 10;
Console.WriteLine(Bonus(score));
Console.WriteLine(score);

int Bonus(int points)
{
    points = points * 2;
    return points;
}

20 10

Expecting 20 20: points is a copy of score, so doubling it changes only the copy; Bonus returns 20, and score stays 10.
Expecting 10 10 or a compile error: a parameter is an ordinary variable of the method, so it can be assigned, and Bonus returns the new value.

JuniorTheoryCommon

int score = 10;
Console.WriteLine(Bonus(score));
Console.WriteLine(score);

int Bonus(int points)
{
    points = points * 2;
    return points;
}

20 10

Expecting 20 20: points is a copy of score, so doubling it changes only the copy; Bonus returns 20, and score stays 10.
Expecting 10 10 or a compile error: a parameter is an ordinary variable of the method, so it can be assigned, and Bonus returns the new value.