Đề 1:

Tính tổng:

program Hello;
uses math;
var a,b:longint;
function sum(a,b:longint): longint;
begin
    sum:=a+b;
end;
begin
    readln(a,b);
    writeln(sum(a,b));
end.

Tìm max:

program Hello;
uses math;
var a,b,c:longint;
function max(a,b:longint): longint;
begin
    if a > b then
        max:= a
    else
        max:= b;
end;
begin
    readln(a,b,c);
    writeln(max(max(a,b),max(b,c)));
end.

===========================

Đề 2:

Tính tích:

program Hello;
uses math;
var a,b:longint;
function p(a,b:longint): longint;
begin
    p:=a*b;
end;
begin
    readln(a,b);
    writeln(p(a,b));
end.

Tìm Min:

program Hello;
uses math;
var a,b,c:longint;
function min(a,b:longint): longint;
begin
    if a < b then
        min:= a
    else
        min:= b;
end;
begin
    readln(a,b,c);
    writeln(min(min(a,b),min(b,c)));
end.