Bài 1:

Thuật toán:

if (a>b) and (a>c) and (a>d) then write('Ban Hoang cao nhat, voi chieu cao la: ',a:0:2) 
else if (b>a) and (b>c) and (b>d) then write('Ban Minh cao nhat, voi chieu cao la: ',b:0:2) 
else if (c>a) and (c>b) and (c>d) then write('Ban Duc cao nhat, voi chieu cao la: ',c:0:2) 
else if (d>b) and (d>c) and (d>a) then write('Ban Long cao nhat, voi chieu cao la: ',d:0:2);

Chương trình:

uses crt;
var a,b,c,d:real;
begin
clrscr;
write('Nhap chieu cao cua Hoang : '); 
readln(a);
write('Nhap chieu cao cua Minh : '); 
readln(b);
write('Nhap chieu cao cua Duc : '); 
readln(c);
write('Nhap chieu cao cua Long : '); 
readln(d);
if (a>b) and (a>c) and (a>d) then write('Ban Hoang cao nhat, voi chieu cao la: ',a:0:2) 
else if (b>a) and (b>c) and (b>d) then write('Ban Minh cao nhat, voi chieu cao la: ',b:0:2) 
else if (c>a) and (c>b) and (c>d) then write('Ban Duc cao nhat, voi chieu cao la: ',c:0:2) 
else if (d>b) and (d>c) and (d>a) then write('Ban Long cao nhat, voi chieu cao la: ',d:0:2);
readln;
end.

Bài 2:

uses crt;
var A,B,C:array[1..12] of integer;
s,s1,s2,i:integer;
t:real;
begin
clrscr;
s:=0; s1:=0; s2:=0; t:=0;
for i:=1 to 12 do
begin
write('Cuoc phi dien thoai thang ',i,' la: '); readln(A[i]);
write('Dien thap sang thang ',i,' la: '); readln(B[i]);
write('Dich vu internet ',i,' la: '); readln(C[i]);
s:=s+A[i]; 
s1:=s1+B[i]; 
s2:=s2+C[i]; 
end;
writeln('So tien Cuoc phi dien thoai la: ',s);
writeln('So tien Dien thap sang la: ',s1);
writeln('So tien Dich vu internet la: ',s2);
write('Dich vu co tong chi lon nhat la: ');
if (s>s1) and (s>s2) then writeln('Cuoc phi dien thoai') 
else if (s1>s) and (s1>s2) then writeln('Dien thap sang')
else if (s2>s) and (s2>s1) then writeln('Dich vu internet');
t:=(s+s1+s2)/12;
write('Trung binh moi thang gia dinh ban An phai tra: ',t:0:2);
readln;
end.