Which of the following is an example of spooled device?

A counting semaphore was initialized to 10. Then 6 P (wait) operations and 4 V (signal) operations were completed on this semaphore. The resulting value of the semaphore

What is the result of the following program?

program side-effect (input, output);
var x, result: integer:
fucntion f (var x:integer):integer;
begin
    x:x+1;f:=x;
end
begin
    x:=5
    result:=f(x)*f(x)
    writeln(result)
end

Faster access to non-local variables is achieved using an array of pointers to activation records called a