Bài 1: 

uses crt;

var n,i,s:integer;

begin

clrscr;

write('Nhap n='); readln(n);

s:=0;

i:=1;

while i<=n do 

  begin

s:=s+i;

inc(i);

end;

writeln('Tong cac so trong khoang tu 1 den ',n,' la: ',s);

readln;

end.

Bài 2: 

uses crt;

var n,i,s:integer;

begin

clrscr;

write('Nhap n='); readln(n);

s:=0;

i:=1;

while i<=n do 

  begin

s:=s+i;

i:=i+2;

end;

writeln('Tong cac so le trong khoang tu 1 den ',n,' la: ',s);

readln;

end.

alo

program tim_uoc;

uses crt;

var i,n,tong:integer;

begin

clrscr;

write('nhap so n:');readln(n);

i:=1;tong:=0;

writeln('cac uoc cua ',n,' la:');

while i<=n do

if n mod i=0 then

begin

write(i:3);

inc(i);

end;

writeln;

i:=1;writeln('cac uoc chan:');

while i<=n do

begin

if n mod i=0 then 

begin

if i mod 2=0 then write(i:3);

tong:=tong+i;

end;

end;

writeln;

write('tong cac uoc chan:',tong);

readln;

end.

uses crt;

var n,i,t:integer;

begin

clrscr;

write('Nhap n='); readln(n);

i:=1;

writeln('Cac uoc cua ',n,' la: ');

while i<=n do

  begin

if n mod i=0 then write(i:4):

i:=i+1;

end;

writeln;

writeln('Cac uoc chan cua ',n,' la: ');

t:=0;

i:=1;

while i<=n do 

  begin

if (n mod i=0) then

begin

t:=t+i;

write(i:4);

end;

inc(i);

end;

writeln('Tong cac uoc chan cua ',n,' la: ',t);

readln;

end.

uses crt;

var n,i,s:integer;

begin

clrscr;

write('Nhap n='); readln(n);

s:=0;

i:=1;

while i<=n do 

  begin

s:=s+i;

inc(i);

end;

writeln(s);

readln;

end.

ae nào giúp mình với ạ'

program DemSoChiaHetCho5;
var
  n, i, count: integer;
begin
  write('Nhap n: ');
  readln(n);
  
  i := 1;
  count := 0;
  while i <= n do
  begin
    if i mod 5 = 0 then
      count := count + 1;
    i := i + 1;
  end;
  
  writeln('Co ', count, ' so tu nhien chia het cho 5 trong khoang tu 1 den ', n);
end.

Program HOC24;

var p: longint;

i,x: integer;

Begin

write('Nhap X: '); readln(X);

p:=1;

for i:=3 to x do if i mod 2=1 then p:=p*i;

write('P = ',p);

readln

end.

Câu 3: 

uses crt;

var n,i,kt:integer;

begin

clrscr;

write('Nhap n='); readln(n);

if n>1 then 

begin

kt:=0;

for i:=2 to trunc(sqrt(n)) do 

  if n mod i=0 then kt:=1;

if kt=0 then writeln(n,' la so nguyen to')

else writeln(n,' la hop so');

end

else writeln(n,' khong la so nguyen to cung khong la hop so');

readln;

end.

Cách 1 dùng lệnh for do:

Uses crt;

var i,n,k: integer;

begin clrcsr;

readln(n);

for i:=1 to n do begin

if(i mod 2=0) and (i>=10) then k:=k*i;

end;

writeln(k);

readln;

end.

Cách 2 dùng lệnh while do

Uses crt;

var m,n,o: integer;

begin clrcsr;

readln(n);

o:=1;

m:=1;

while (m<n) do begin

m:=m+1;

if(m mod 2=0) and (m>=10) then o:=o*m;

end;

writeln(o);

readln;

end.

#include <bits/stdc++.h>

using namespace std;

int main()

{

int n,t=0,i,dem=0;

cin>>n;

for (int i=1; i<=n; i++)

if (i%2==0)

{

t=t+i;

dem++;

}

cout<<fixed<<setprecision(2)<<(t*1.0)/(dem*1.0);

return 0;

}

program Le_Nho_Hon_Hoac_Bang_n;

uses crt;

var

       n, i: integer;

begin

       clrscr;

       write('Nhap vao mot so nguyen duong n: ');

       readln(n);

       while n <= 0 do

       begin

              writeln('So ban nhap khong hop le. Xin vui long nhap lai: ');

              readln(n);

       end;

       clrscr;

       writeln('Cac so le nho hon hoac bang ', n, ' la:');

       i := 1;

       while i <= n do

       begin

              if i mod 2 <> 0 then

                     writeln(i);

              i := i + 1;

       end;

       readln;

end.