В двумерном массиве хранится информация о количестве студентов в той или иной группе

procedure TForm1.Button1Click(Sender: TObject);
Var
  Students: array[1..5,1..10] of integer;
  Students_count, i, j: integer;
begin
  for I := 1 to 5 do
    for j := 1 to 10 do
    Students[i, j] := 0;
 
  Students[5, 2] := 12; // 12 человек в 2й группе 5го курса
  Students[5, 5] := 16;
  Students[5, 8] := 20;
 
  Students_count := 0;
 
 for j := 1 to 10 do
  if Students[5, j] > 0 then Students_count := Students_count + Students[5, j];
 
  Label1.Caption := IntToStr(Students_count);
end;

procedure TForm8.Button1Click(Sender: TObject);
var
 a:array[1..10,0..4] of integer;
i,j:integer;
begin
for i := 1 to 10 do
for j := 0 to 4 do
a[i,j]:=Random(10)+30;
for i := 1 to 10 do
for j := 0 to 4 do
StringGrid1.Cells[j,i]:=inttostr(a[i,j]);
end;.

var
a:array[1..10,0..4] of integer;
sum,i,j:integer;
begin
Randomize;
sum:=0;
for i := 1 to 10 do
for j := 0 to 4 do begin
a[i,j]:=Random(10)+30;
StringGrid1.Cells[j,i]:=inttostr(a[i,j]);
for i:=0 to StringGrid1.RowCount-1 do
  sum:=sum+strtoint(StringGrid1.cell[4,i])
end;

var
sum,i,j:integer;
begin
Randomize;
sum:=0;
for i := 1 to 10 do
    for j := 0 to 4 do
        StringGrid1.Cells[j,i]:=inttostr(Random(10)+30);
for i:=1 to 5 do
  sum:=sum+strtoint(StringGrid1.Cells[4,i]);
showmessage(inttostr(sum));
end;