Which scheduling policy is most suitable for a time-shared operating systems?

The sequence $$.........$$ is an optimal non-preemptive scheduling sequence for the following jobs which leaves the $$CPU$$ idle for $$..........$$ Unit (s) of time

What are x and y in the following macro definition?

macro Add x,y
Load y
Mul x
Store y
end macro

What is the value of X printed by the following program?

program COMPUTE (input, output);
var
    X:integer;
procedure FIND (X:real);
    begin
    X:=sqrt(X);
    end;
begin
   X:=2
   Find(X)
   Writeln(X)
end