Câu 1:

Program HOC24;

var i,p: integer;

t: longint;

begin

write('Nhap P: '); readln(p);

t:=0;

for i:=1 to p do if i mod 2<>0 then t:=t+i;

write('Tong cac so le la: ',t);

readln

end.

Câu 2:

Program HOC24;

var i,n: integer;

t: longint;

begin

write('Nhap N: '); readln(n);

t:=0;

for i:=1 to n do if i mod 2=0 then t:=t+i;

write('Tong cac so chan la: ',t);

readln

end.

Câu 3:

Program HOC24;

var i,t,n: integer;

begin

write('Nhap N: '); readln(n);

t:=0;

for i:=1 to n do if n mod i=0 then t:=t+i;

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

readln

end.

Câu 1: 

program chieu_cao;

uses crt;

var Nam, Linh: real;

begin

clrscr;

write ('Nhap chieu cao cua Nam:'); readln (Nam);

write ('Nhap chieu cao cua Linh:'); readln (Trang);

if Nam > Linh then writeln ('Ban Nam cao hon');

if Nam < Linh then writeln ('Ban Linh cao hon') else writeln ('Hai ban cao bang nhau');

readln

end.

Câu 2: 

program Tich;

var N,i: interger;

      P: longint;

begin

write ('N='); readln (N);

P:=1;

for i:=1 to N do P:=P*i;

writeln (N,' ! = ',P);

readln

end.

Câu 3: 

uses crt;

var n,i,s:longint;

begin

clrscr;

readln(n);

for i:=1 to 10 do 

  writeln(n,'*',i,'=',n*i);

readln;

end.

Program HOC24;

var i,n: integer;

tong,tich: longint;

begin

write('Nhap N: '); readln(n);

tong:=0; tich:=1;

for i:=1 to n do 

begin

tong:=tong+i;

tich:=tich*i;

end;

writeln('Tong la: ',tong);

write('Tich la: ',tich);

readln

end.

program TinhTongTichTu1DenN;
var n, i: integer;
       tong, tich: longint;
begin
  tong := 0;
  tich := 1;

  write('Nhap vao n: ');
  readln(n);
  for i := 1 to n do
  begin
    tong := tong + i;
    tich := tich * i;
  end;

  writeln('Tong cac so tu 1 den ', n, ': ', tong);
  writeln('Tich cac so tu 1 den ', n, ': ', tich);

  readln;
end.

program TinhTongTich;

var

      N, i, Tong, Tich:integer;

begin

      writeln('Nhap so nguyen duong N:');

      readln(N);

      i:=1;

      Tong:=0;

      Tich:=1;

      while i<=N do

      begin

            Tong:=Tong+i;

            Tich:=Tich*i;

            i:=i+1;

      end;

      writeln('Tong cac so tu 1 den ', N, ' la: ', Tong);

      writeln('Tich cac so tu 1 den ', N, ' la: ', Tich);

      readln;

end.

Bài 1:

uses crt;

var i,s:integer;

begin

clrscr;

s:=0;

for i:=10 to 50 do

  if i mod 2=0 then s:=s+i;

writeln(s);

readln;

end.

Bài 2: 

uses crt;

var a,i,n:integer;

begin

clrscr;

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

a:=0;

for i:=1 to n do

a:=a+i*(i+2);

writeln(a);

readln;

end.

Câu 1: 

uses crt;

var s,i:integer;

begin

clrscr;

s:=0;

for i:=1 to 10 do 

  s:=s+i;

writeln('Tong cua 10 so tu nhien dau tien la: ',s);

readln;

end.

Câu 2: 

uses crt;

var a:array[1..100]of integer;

i,n,dem:integer;

begin

clrscr;

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

for i:=1 to n do 

  begin

write('A[',i,']='); readln(a[i]);

end;

dem:=0;

for i:=1 to n do

if a[i]>0 then inc(dem);

writeln('So luong phan tu duong la: ',dem);

readln;

end.

Câu 3: 

uses crt;

var i,j:integer;

begin

clrscr;

for i:=1 to 9 do 

  begin

      writeln('Bang nhan ',i,' la: ');

for j:=1 to 10 do 

  writeln(i,'*',j,'=',i*j);

delay(200);

end;

readln;

end.

Câu 1: 
uses crt;
var s,i,n:integer;
begin clrscr;
s:=0;
write('Nhap n: ');readln(n);
for i:=1 to n do
if i mod 2 <> 0 then inc(s,i);
write('Tong cac so le tu 1 den ',n,' la: ',s);
readln
end.

Câu 2:
uses crt;
var s,i,n:integer;
begin clrscr;
s:=0;
write('Nhap n: ');readln(n);
for i:=1 to n do
if i mod 2 = 0 then inc(s,i);
write('Tong cac so le tu 1 den ',n,' la: ',s);
readln
end.

Bài 1: 

uses crt;

var n,t1,t2,t3,i:integer;

begin

clrscr;

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

t1:=0;

t2:=0;

for i:=1 to n-1 do 

  begin

if i mod 2=1 then t1:=t1+i

else t2:=t2+i;

end;

writeln('Tong cac so le nho hon ',n,' la: ',t1);

writeln('Tong cac so chan nho hon ',n,' la: ',t2);

t3:=0;

for i:=1 to 2*n do 

  t3:=t3+i;

writeln('Tong cac so trong day so tu 1 toi 2*',n,' la: ',t3);

readln;

end.

#include <bits/stdc++.h>

using namespace std;

long long i,n,s;

int main()

{

cin>>n;

s=0;

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

if (i%2==0) s=s+i;

cout<<s;

return 0;
}