Program Tong_cac_so_tu_nhien;

Uses CRT;

Var i,d: Byte;

Begin

d:=0;

For i = 10 to 99 Do d:=d+i;

Writeln('Tong cac so tu nhien tu 10 den 99 la ',d);

End.

uses crt;

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

i,n,t,dem1,t1:integer;

begin

clrscr;

readln(n);

for i:=1 to n do readln(a[i]);

for i:=1 to n do 

if a[i]>0 then write(a[i]:4);

writeln;

t:=0;

for i:=1 to n do 

  t:=t+a[i];

writeln('Trung binh cua day la: ' ,t/n:4:2);

t1:=0;

dem1:=0;

for i:=1 to n do 

  if a[i]>0 then 

begin

t1:=t1+a[i];

inc(dem1);

end;

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

readln;

end. 

uses crt;

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

i,n,t,dem1,t1:integer;

begin

clrscr;

readln(n);

for i:=1 to n do readln(a[i]);

for i:=1 to n do 

if a[i]>0 then write(a[i]:4);

writeln;

t:=0;

for i:=1 to n do 

  t:=t+a[i];

writeln('Trung binh cua day la: ' ,t/n:4:2);

t1:=0;

dem1:=0;

for i:=1 to n do 

  if a[i]>0 then 

begin

t1:=t1+a[i];

inc(dem1);

end;

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

readln;

end. 

TK

có thể ghi cho mik đc ko

i:=1;

Lỗi là giá trị đầu và giá trị cuối trong vòng for là số thực

Chọn D

uses crt;

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

i,n,dem1,dem2,dem3,dem4:integer;

begin

clrscr;

readln(n);

for i:=1 to n do readln(a[i]);

dem1:=0;

dem2:=0;

dem3:=0;

dem4:=0;

for i:=1 to n do 

  begin

 if (a[i]>=8) then inc(dem1);

if (6.5<=a[i]) and (a[i]<=7.9) then inc(dem2);

if (5<=a[i]) and (a[i]<=6.4) then inc(dem3);

if (a[i]<5) then inc(dem4);

end;

writeln('So hoc sinh gioi la: ',dem1);

writeln('So hoc sinh kha la: ',dem2);

writeln('So hoc sinh trung binh la: ',dem3);

writeln('So hoc sinh kem la: ',dem4);

readln;

end.

uses crt;

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

i,n:integer;

begin

clrscr;

readln(n);

for i:=1 to n do readln(a[i]);

for i:=1 to n do write(a[i]:4);

writeln;

writeln('Phan tu thu hai la: ',a[2]);

readln;

end.

#include <bits/stdc++.h>

using namespace std;

long long i,n;

double a;

int main()

{

cin>>n;

a=0;

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

a=a+1/((i*1.0)*((i+1)*1.0));

cout<<fixed<<setprecision(2)<<a;

return 0;

}