a)

uses crt;

VAR

n, d, i: integer;

BEGIN

clrscr;

Writeln ('Nhap vao n='); readln (n);

d : = 1;

For i: = 1 to n do

d: = d*i;

Writeln ('d=',d);

Readln;

END.

c)

uses crt;

VAR

n, i, demuoc: integer;

BEGIN

clrscr;

Writeln ('Nhap vao n='); readln (n);

demuoc: = 0;

For i: = 1 to n do

If n mod i = 0 then

demuoc : = demuoc + 1;

If demuoc = 2 then

Writeln ('n la so nguyen to')

ELSE

Writeln ('n khong phai la so nguyen to');

Readln ;

END.

Còn phần b bạn tự nghĩ nha!

Chúc bạn học tốt!

2:

#include <bits/stdc++.h>

using namespace std;

int main()

{

int n,i,kt=0;

cin>>n;

for (int i=2; i*i<=n; i++)

if (n%i==0) kt=1;

if (kt==0) cout<<"YES";

else cout<<"NO";

}

Bài 1:

uses crt;

var n,i,s:integer;

begin

clrscr;

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

s:=0;

for i:=1 to n do 

 if i mod 6=0 then s:=s+i;

writeln(s);

readln;

end.

Bài 2: 

uses crt;

var a,b,c,ucln,i:integer;

begin

clrscr;

write('a='); readln(a);

write('b='); readln(b);

write('c='); readln(c);

while a<>b do 

  begin

if a>b then a:=a-b

else b:=b-a;

end;

ucln:=a;

while ucln<>c do 

 begin

if ucln>c then ucln:=ucln-c

else c:=c-ucln;

end;

writeln(ucln);

readln;

end.

Scratch hay java

#include <bits/stdc++.h>

using namespace std;

long long n,i;

int main()

{

cin>>n;

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

if (i%3==0) cout<<i<<" ";

return 0;

}

#include <bits/stdc++.h>

using namespace std;

long long n,i;

int main()

{

cin>>n;

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

if (i%3==0) cout<<i<<" ";

return 0;

}

#include <bits/stdc++.h>

using namespace std;

long long n,i;

int main()

{

cin>>n;

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

if (i%3==0) cout<<i<<" ";

return 0;

}

Program Tin_hoc;

Uses Crt;

Var N: Integer;

Begin

        Write('Nhap so nguyen N');

        Readln(N);

        If N>0 then write(' So do la so duong ');

        If N<0 then write(' So do la so am ');

        If N=0 then write(' So do khong la so am va so duong');

        Readln;

End.

Program Tin_hoc;

Uses Crt;

Var N: Integer;

Begin

        Write('Nhap so nguyen N');

        Readln(N);

        If N>0 then write(' So do la so duong ');

        If N<0 then write(' So do la so am ');

        If N=0 then write(' So do khong la so am va so duong');

        Readln;

End.

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;

}

Cau 1:

Câu 2:

#include <bits/stdc++.h>

using namespace std;

long long n;

int main()

{

cin>>n;

if (n>0 && n%5==0) cout<<"Phai";

else cout<<"Khong phai";

}