Lời giải :
+ for-do :
program hotrotinhoc ;
var i,tong : integer ;
begin
tong:=0;
for i:= 10 to 100 do tong:=tong+i;
write('Tong=',tong);
readln
end.
+ While-do :
program hotrotinhoc ;
var i,tong : integer ;
begin
tong:=0; i:=9;
while i<100 do
begin
i:=i+1;
tong:=tong+i;
end;
write('Tong=',tong);
readln
end.