Question

Answer 1

uses crt;

var n,i,t:integer;

{----------------chuong-trinh-con-kiem-tra-so-nguyen-to----------------------}
function ktnt(x:integer):boolean;

var kt:boolean;

n,i:integer;

begin

kt:=true;

for i:=2 to x-1 do 

  if x mod i=0 then kt:=false;

if kt=true then ktnt:=true

else ktnt:=false;

end;

{------------------chuong-trinh-chinh---------------------}

begin

clrscr;

write('Nhap n='); readln(n);

t:=0;

for i:=2 to n do 

 if ktnt(i)=true then 

begin

write(i:4);

t:=t+i;

end;

writeln;

writeln('Tong cac so nguyen to la: ',t);

readln;

end.