Operators - General Questions

What is the output of the following program?

int x = 7;
Console.WriteLine(x > 5 ? "big" : "small");

What is the output of the following program?

Console.WriteLine(1 << 4);

What is the output of the following program?

int a = 5;
int b = a++;
Console.WriteLine(a + " " + b);

What is the output of the following program?

int x = 5;
int y = x++ + ++x;
Console.WriteLine($"{x} {y}");

What is the output of the following program?

string s = null;
Console.WriteLine(s?.Length ?? -1);