program bai1;
uses crt;
var A:array[1..100] of integer;
i,n:byte;
tong,trungbinh:real;
begin
clrscr;
write(`Nhap vao so luong phan tu cua mang, n=`);
readln(n);
tong:=0;
for i:=1 to n do
begin
write(`Nhap vao phan tu thu`, i,`=`);
readln(A[i]);
tong:=tong+A[i];
end;
trungbinh:=tong/n;
Write(`Gia tri trung binh cua cac phan tu trong mang la=`, trungbinh:5:2);
readln;
end.
Program bai2;
uses crt;
var A:array[1..20] of integer;
i,n:byte;
tong:real;
begin
clrscr;
write(`Nhap vao so luong phan tu cua mang, n=`);
readln(n);
tong:=0;
for i:=1 to n do
begin
write(`Nhap vao phan tu thu`, i,`=`);
readln(A[i]);
if (A[i]>0) and (A[i] mod 2=0) then
tong:=tong+A[i];
end;
Write(`Tong gia tri cac phan tu chan va duong la `, tong:4:2);
readln;
end.
Program bai3;
uses crt;
var A:array[1..100] of integer;
i,n,dem:byte;
x:real;
begin
clrscr;
write(`Nhap vao so luong phan tu cua mang, n=`);
readln(n);
dem:=0;
write(`Nhap x=`);
readln(x);
for i:=1 to n do
begin
write(`Nhap vao phan tu thu`, i,`=`);
readln(A[i]);
if A[i]=x then dem:=dem+1;
end;
Write(`So phan tu trong mang co gia tri bang x la `, dem);
readln;
end.






program bai4;
uses crt;
var A:string;
i,n:byte;
begin
clrscr;
write(`nhap xau A:`);
readln(A);
n:=length(A);
for i:=n downto 1 do write(A[i]);
readln;
end.
program bai5;
uses crt;
var A:string;
i:byte;
begin
clrscr;
write(`nhap xau A:`);
readln(A);
for i:=1 to length(A) do write(upcase(A[i]));
readln;
end.
Program bai7;
Uses CRT;
Type
Banghi=record
Hoten:string[30];
Diachi:string[60];
cu,moi,chiso:word;
tien:longint;
end;
var hoadon:array[1..50] of banghi;
i,n:integer;
Begin
clrscr;
write(`So luong khach hang su dung dien la:`);
readln(n);
for i:=1 to n do
begin
write(`Nhap thong tin nguoi thu`,i);
write(`Hoten:`); readln(hoadon[i].hoten);
write(`Diachi:`); readln(hoadon[i].diachi);
write(`Chi so cu:`); readln(hoadon[i].cu);
write(`Chi so moi:`); readln(hoadon[i].moi);
hoadon[i].chiso:=hoadon[i].moi-hoadon[i].cu;
if hoadon[i].chiso<=20 then hoadon[i].tien:=hoadon[i].chiso*500;
if (hoadon[i].chiso>20) and (hoadon[i].chiso<=50) then hoadon[i].tien:=20*500+(hoadon[i].chiso-20)*700;
if hoadon[i].chiso>50 then hoadon[i].tien:=20*500+30*700+(hoadon[i].chiso-50)*1000;
end;
writeln;
for i:=1 to n do
begin
write(`ho ten:`,hoadon[i].hoten:30,