Bài 3 :

uses crt;
var n,i,sl : integer;
a : array[1..100] of real;
x,t : real;
begin clrscr;
t:=0; sl:=0;
write('Nhap n:'); readln(n);
for i:=1 to n do begin write('Nhap a[',i,']='); readln(a[i]);
end;
write('Nhap X:'); readln(x);
for i:=1 to n do if a[i] < x then begin
sl:=sl+1;
t:=t+a[i];
write(a[i]:2);
end;
write('Co ',sl,' phan tu khong lon hon X');
write('Tong cac phan tu la :', t);
readln
end.

Bài 4 :

uses crt;
var n,i,sl : integer;
a : array[1..100] of real;
x,t : real;
begin clrscr;
t:=0; sl:=0;
write('Nhap n:'); readln(n);
for i:=1 to n do begin write('Nhap a[',i,']='); readln(a[i]);
end;
for i:=1 TO N DO IF A[I]  >=8.0 then begin
sl:=sl+1;
write(a[i]:3);
end;
write('Co ',sl,' em dat hoc sinh gioi');
readln
end.

3.

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n,a=0,total=0;
    float x;
    cin>>n>>x;
    float arr[n];
    for(int i=0;i<n;i++){
        cin>>arr[i];
        if(arr[i]<=x){
            a++;
            total+=arr[i];
        }
    }
    cout<<"Co "<<a<<" phan tu khong lon hon "<<x<<": ";
    for(int i=0;i<n;i++){
        if(arr[i]<=x){
            cout<<arr[i]<<" ";
        }
    }
    cout<<"\nTong: "<<total;
    //samon247
    return 0;
}

4.

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n,a=0;
    cin>>n;
    float arr[n],x=8.0;
    for(int i=0;i<n;i++){
        cin>>arr[i];
        if(arr[i]>=x){
            a++;
        }
    }
    cout<<"Co "<<a<<" ban dat loai Gioi"<<endl;
    for(int i=0;i<n;i++){
        if(arr[i]>=x){
            cout<<"HS"<<i+1<<": "<<arr[i]<<endl;
        }
    }
    //samon247
    return 0;
}