program bai_tap;
var i,d:integer;
begin
d:=0;
for i:= 100 to 999 do
begin
if (i mod 2 = 0) and (i mod 3 = 0) and (i mod 5 = 0 ) then
begin
write(i,' ');
inc(d);
end;
if d = 5 then
begin
d:=0;
writeln;
end;
end;
readln
end.

program bai_tap;
var t,k:integer;
begin
assign(input,'DULIEU.TXT');
reset(input);
assign(output,'KETQUA.TXT');
rewrite(output);
t:=0;
while not eof(input) do
begin
read(k);
t:=t+sqr(k);
end;
write(t);
close(output);
end.

program bai_tap;
var i,x,y:integer;
begin
assign(output,'D:\A.txt');
rewrite(output);
for i:= 1 to 3 do
begin
read(x,y);
writeln(x,' ',y);
end;
close(output);
end.

program bai_tap;
i,d1,d2:integer;s:string;
begin
writeln('nhap s:');
readln(s);
d1:=0;d2:=0;
for i:= 1 to length(s) do
if s[i] in ['A'..'Z'] then inc(d1)
else inc(d2);
writeln('co ',d1,' ki tu hoa');
writeln('co ',d2,' ki tu thuong');
readln
end.

ý tưởng:
-gọi d1 là số kí tự hoa,d2 là số kí tự thường
-cho biến i chạy từ 1 đến length(s)
-if s[i] in ['A'..'Z'] then inc(d1) else inc(d2);

program bai_tap;
n:integer;
begin
writeln('nhap n:');
readln(n);
if n mod 2 = 0 then
writeln(n,': la so chan')
else write(n,': la so le');
readln
end.

program bai_tap;
type mang = array[1..1000] of integer;
var a:mang;
i,j,n:integer;kt:boolean;
begin
writeln('nhap n:');
readln(n);
i:=1;
while i <= n do
begin
write('nhap so thu ',i,': ');
readln(a[i]);
if a[i] > 1 then
begin
kt:=true;
for j:= 2 to trunc(sqrt(a[i])) do
if a[i] mod j = 0 then
begin
kt:=false;
break;
end;
if kt = true then writeln(a[i]);
end;
inc(i);
end;
readln
end.

program bai_tap;
type mang = array[1..1000] of integer;
var a:mang;
i,j,n:integer;
begin
writeln('nhap n:');
readln(n);
i:=1;j:=0;
while i <= n do
begin
write('nhap so thu ',i,': ');
readln(a[i]);
if a[i] mod 2 = 0 then j:=j+a[i];
inc(i);
end;
write(j);
readln
end.

C.String nhé

câu 4)

program bai_tap;
uses crt;
var n,i:byte;
k:integer;
a:array[1..100] of integer;
begin
clrscr;
write('nhap so luong phan tu cua mang: ');
readln(n);
for i:= 1 to n do
begin
write('A[',i,'] = ');
write(a[i]);
end;
write('nhap gia tri phan tu K: ');
readln(K);
for i:= 1 to n do
if a[i] = k then
begin
write('vi tri cua K la: ',i);
break; {vì tìm 1 phần tử}
end;
readln
end.