Dalibor31

program Benchmark;

{$APPTYPE CONSOLE}

uses
  SysUtils, DateUtils;

var
  StartTime, EndTime: TDateTime;
  Total: Int64;
  NumOfIterations3, NumOfIterations5, NumOfIterations15: Int64;
  Sum3, Sum5, Sum15: Int64;
  Duration: Double;
  Key: Char;

begin
  // Start measuring time
  StartTime := Now;

  NumOfIterations3 := 1000000000 div 3;
  NumOfIterations5 := 1000000000 div 5;
  NumOfIterations15 := 1000000000 div 15;

  Sum3 := NumOfIterations3 * (NumOfIterations3 + 1) div 2 * 3;
  Sum5 := NumOfIterations5 * (NumOfIterations5 + 1) div 2 * 5;
  Sum15 := NumOfIterations15 * (NumOfIterations15 + 1) div 2 * 15;

  Total := Sum3 + Sum5 - Sum15;

  // Stop measuring time
  EndTime := Now;
  Duration := SecondsBetween(EndTime, StartTime);
  Writeln('Total: ', Total);
  Writeln('Time taken: ', Duration:0:6, ' seconds');

  Write('Press any key to exit');
  Readln(Key);
end.

What about this code optimization?