15)

uses crt;

var i,n,s: integer;

begin

clrscr;

write ('nhap n: ');  readln (n);

s:=1;

for i:=1 to n do

s:=s*i;

Write ('tich la: ',s);

readln;

end.

16)

uses crt;

var i,n,s: integer;

begin

clrscr;

s:=0;

i:=100;

while i<=1000 do

begin

s:=s+i;

i:=i+1;

end;

writeln ('tong la: ',s);

readln;

end.

17)

uses crt;

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

i,n: integer;

tb: real;

begin

clrscr;

write ('nhap so luong phan tu: ');  readln (n);

tb:=0;

for i:=1 to n do

begin

write ('nhap phan tu thu ',i,': ');  readln (a[i]);

tb:=tb+a[i];

end;

tb:=tb/n;

writeln ('Trung binh la: ',tb:1:2);

readln;

end.

18)

uses crt;

var i,n,d1,d2: integer;

begin

clrscr;

write ('nhap n: ');  readln (n);

d1:=0;

d2:=0;

for i:=1 to n do

begin

if i mod 2=0 then d1:=d1+1;

if (i mod 3=0) and (i mod 5=0) then d2:=d2+1;

end;

Writeln ('Co ',d1,' so chia het cho 2');

writeln ('Co ',d2,' so chia het cho 3 va 5');

readln;

end.

$#Trumtinhoc$

câu 15:

uses crt;

var n,i,s: integer;

begin

clrscr;

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

for i:=1 to n do s:=s+i;

write('tong ',n,' so tu nhien dau tien la: ',s);

readln;

end.

câu 16:

uses crt;

var i,s,n: int64;

begin

clrscr;

n:=100;

i:=100;

while n<=1000 do

begin

s:=s+i;

i:=i+1;

n:=n+1;

end;

write('tong cac so tu 100 toi 1000 la: ',s);

readln;

end.

câu 17:

uses crt;

var n,i,s: integer;

A: array [1..1000] of integer;

begin

clrscr;

write('nhap do dai day so: '); readln(n);

for i:=1 to n do

begin

write('nhap so thu ',i,': '); readln(A[i]);

s:=s+A[i];

end;

write('trung binh cong cua day so tren la: ',s/n:3:1);

readln;

end.

câu 18:

uses crt;

var i,n,t1,t2: integer;

begin

clrscr;

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

for i:=1 to n do

begin

if (i mod 2 = 0) then t1:=t1+1;

if (i mod 3 = 0) and (i mod 5 = 0) then t2:=t2+1;

end;

writeln('co ',t1,' so chia het cho 2');

write('co ',t2,' so chia het cho 3 va 5');

readln;

end.