c1: 

#include <bits/stdc++.h>

using namespace std;

long long i,n,s;

int main()

{

cin>>n;

s=1;

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

cout<<s;

return 0;

}

Câu 2: 

#include <bits/stdc++.h>

using namespace std;

long long i,n,s;

int main()

{

cin>>n;

s=1;

for (i=1; i<=n; i++) if (i%2==0) s=s*i;

cout<<s;

return 0;

}

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

uses crt;

var n,i,s:integer;

begin

clrscr;

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

s:=0;

for i:=1 to n do  

  s:=s+i;

writeln(s);

readln;

end.

2:

#include <bits/stdc++.h>

using namespace std;

long long n,i;

int main()

{

cin>>n;

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

if (n%i==0) cout<<i<<" ";

return 0;

}

1. Uses crt;

var n,i: integer;

begin clrscr;

readln(n);

for i:=1 to n do write(i:3);

readln;

end.

2. Uses crt;

var n,i: integer;

begin clrscr;

readln(n);

for i:=1 to n do if(i mod 2 = 0) then write(i:3);

readln;

end.

1. Uses crt;

var n,i: integer;

begin clrscr;

readln(n);

for i:=1 to n do write(i:3);

readln;

end.

2. Uses crt;

var n,i: integer;

begin clrscr;

readln(n);

for i:=1 to n do if(i mod 2 = 0) then write(i:3);

readln;

end.

1.

program InDaySoTuNhien;
var n, i: integer;
begin
   write('Nhap so nguyen duong n: ');
   readln(n);

   writeln('Day so tu 1 den ', n, ' la:');
   for i := 1 to n do
      write(i, ' ');
end.

2.

program InSoChan;
var
   n, i: integer;
begin
   write('Nhap so nguyen n: ');
   readln(n);

   writeln('Cac so nguyen chan trong khoang tu 1 den ', n, ' la:');
   for i := 1 to n do
   begin
      if i mod 2 = 0 then
         write(i, ' ');
   end;
end.

Bài 1: 

uses crt;

var n,i:integer;

s:real;

begin

clrscr;

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

s:=0;

for i:=1 to n do 

  s:=s+1/(2*i+1);

writeln(s:4:2);

readln;

end.

uses crt;

var a:array[1..200]of integer;

n,i,k,t,t1:integer;

begin

clrscr;

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

for i:=1 to n do 

  begin

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

end;

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

t:=0;

for i:=1 to n do 

  if a[i] mod 2<>0 then t:=t+a[i];

t1:=0;

for i:=1 to n do 

  if a[i] mod k=0 then t1:=t1+a[i];

writeln('Tong cac phan tu le la: ',t);

writeln('Tong cac phan tu la boi cua ',k,' la: ',t1);

readln;

end.

2: 

#include <bits/stdc++.h>

using namespace std;

int main()

{

string st;

int a;

cin>>st;

cin>>a;

cout<<"Xin chao "<<st<<endl;

cout<<"Nam nay "<<st<<" "<<2021-a<<" tuoi";

return 0;

}

Bài 1: 

#include <bits/stdc++.h>

using namespace std;

long long i,n,x,t;

int main()

{

cin>>n;

t=0;

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

{

cin>>x;

if (x%15==0) t=t+x;

}

cout<<t;

return 0;

}

2:

#include <bits/stdc++.h>

using namespace std;

long long a,b;

int main()

{

cin>>a>>b;

cout<<a%b<<endl;

cout<<a/b;

return 0;

}