Program HOC24;

var b: real;

i,n: integer;

begin

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

b:=0;

for i:=1 to n do b:=b+1/(i+2);

write('B= ',b:1:2);

readln

end.

Câu 1: 

uses crt;

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

i,n,t,s:integer;

begin

clrscr;

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

for i:=1 to n do 

  begin

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

end;

t:=0;

s:=1;

dem:=0;

for i:=1 to n do 

  if a[i] mod 3=0 then 

begin

inc(dem);

t:=t+a[i];

s:=s*a[i];

end;

if dem=0 then writeln('Khong co so chia het cho 3 trong day')

else begin

writeln('Tong cac so chia het cho 3 la: ',t);

writeln('Tich cac so chia het cho 3 la: ',s);

end;

readln;

end.

Câu 2: 

uses crt;

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

i,n,dem,t:integer;

begin

clrscr;

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

for i:=1 to n do 

  begin

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

end;

dem:=0;

t:=0;

for i:=1 to n do 

 if a[i] mod 2=0 then 

begin

inc(dem);

t:=t+a[i];

end;

writeln('So so chan la: ',dem);

writeln('Tong cac so chan la: ',t);

readln;

end.

Câu 3: 

uses crt;

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

i,n,dem1,dem2,t1,t2,s1,s2:integer;

begin

clrscr;

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

for i:=1 to n do 

  begin

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

end;

dem1:=0;

dem2:=0;

t1:=0;

t2:=0;

s1:=1;

s2:=1;

for i:=1 to n do

begin

if a[i] mod 2=0 then 

begin

inc(dem1);

t1:=t1+a[i];

s1:=s1*a[i];

end

else begin

inc(dem2);

t2:=t2+a[i];

s2:=s2*a[i];

end;

end;

if dem1=0 then writeln('Khong co so chan trong day')

else begin

writeln('So so chan la: ',dem1);

writeln('Tong cac so chan la: ',t1);

writeln('Tich cac so chan la: ',s1);

end;

if dem2=0 then writeln('Khong co so le trong day')

else begin

writeln('So so le la: ',dem2);

writeln('Tong cac so le la: ',t2);

writeln('Tich cac so le la: ',s2);

end;

readln;

end.

uses crt;

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

i,n,t1,t2,dem1,dem2:integer;

begin

clrscr;

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

for i:=1 to n do 

  begin

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

end;

writeln('Day so vua nhap la: ');

for i:=1 to n do 

  write(a[i]:4);

writeln;

t1:=0;

dem1:=0;

t2:=0;

dem2:=0;

for i:=1 to n do 

 begin

if a[i] mod 2=0 then

begin

t1:=t1+a[i];

inc(dem1);

end

else begin

t2:=t2+a[i];

inc(dem2);

end;

end;

writeln('Trung binh cac so chan la: ',t1/dem1:4:2);

writeln('Trung binh cac so le la: ',t2/dem2:4:2);

readln;

end.

Program Tin_hoc;

Uses crt; 

Var i,n,dem:integer;

      a:array[1..100000] of integer;

Begin

clrscr;

Write('Nhap 1 so nguyen duong n: ');readln(n);

dem:=0;

Writeln('Nhap ',n,' phan tu:');

For i:= 1 to n do 

Begin

Write('A[',i,'] = ');

readln(a[i]);

If a[i] mod 2 = 0 then inc(dem);

End;

Writeln('Day vua nhap la:');

For i:= 1 to n do write(a[i],'  ');writeln;

Writeln('Day so vua nhap co ',dem,' so chan');

readln;

End.

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;

for i:=1 to n do 

 write(a[i]:4);

writeln;

dem:=0;

for i:=1 to n do 

  if a[i] mod 2=0 then inc(dem);

writeln('So so chan la: ',dem);

readln;

end.

uses crt;
Var a:array[1..100000] of longint;
i,n,max:longint;
Begin
clrscr;
write('Nhap n: '); readln(n);
For i:=1 to n do
Begin
Write('A[',i,'] = '); Readln(A[i]);
end;
for i:=1 to n do
if a[i]>max then max:=a[i];
write('Gia tri lon nhat trong day so vua nhap la: ',max);
readln
end.

program tongchan;

uses crt;

var i,n,s:integer;

     a:array[1..50] of integer;

Begin

Write('n=');readln(n);

for i:=1 to n do

Write('a[,'i',]=');readln(a[i]);

s:=0;

for i:=1 to n do 

if a[i] mod 2 = 0 then s:=s+a[i];

if s=0 then write('Trong mang ko co so chan') else write('Tong cac so chan la:,s');

readln;

end.

uses crt;

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

i,n,t,t1:integer;

begin

clrscr;

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

for i:=1 to n do

 begin

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

end;

t:=0;

for i:=1 to n do 

  t:=t+a[i];

t1:=0;

for i:=1 to n do 

  if a[i] mod 2=0 then t1:=t1+a[i];

writeln('Tong cac so la: ',t);

writeln('Tong cac so chan la: ',t1);

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.

uses crt;
var e,f,i,a,b,c,d: byte;
begin
clrscr;
write('Tu so = '); readln(e);
write('Mau so = '); readln(f);
a:=e;
b:=f;
writeln('Phan so ban dau: ',e,'/',f);
while E <> F do
if E > F then E:=E-F
else F:=F-E;
If e <> 1 then
begin
a:=a div e;
b:=b div e;
write('Phan so toi gian: ',a,'/',b);
end
else write('Phan so da toi gian, ',a,'/',b);
readln
end.

uses crt;

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

begin

clrscr;

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

repeat

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

until b<>0;

min:=a;

if min>b then min:=b;

ucln:=1;

for i:=1 to min do 

  if (a mod i=0) and (b mod i=0) then 

begin

if ucln<i then ucln:=i;

end;

writeln(a,'/',b,'=',a div ucln,'/',b div ucln);

readln;

end.