uses crt;
var i,n,x,c,d,j,tam,s:integer;
a:array[1..100] of integer;
begin
clrscr;
write('nhap so n:');readln(n);
write('nhap so x:');readln(x);
for i:=1 to n do
begin
 write('A[',i,']=');
 readln(a[i]);
 if (a[i] >50) and (a[i] mod 10=0) then c:=c+a[i];
 if x=a[i] then d:=d+1;
end;
writeln('tong cac ptu lon hon 50 va chia het cho 10 la:',c);
for i:=1 to n do
for j:=i+1 to n do
 if a[i] < a[j] then
 begin
  tam:=a[i];
  a[i]:=a[j];
  a[j]:=tam;
 end;
write('sap sep theo thu tu giam dan:');
for i:=1 to n do write(a[i]:3);
writeln;
if d>0 then
 write('co ',d,' lan ',x,'  xuat hien trong mang')
else write(x,' ko xuat hien trong mang');
readln;
end.

(mong dc 5*+hay nhất)

uses crt;

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

i,n,j,t,s,x,d: integer;

begin

clrscr;

write ('N= ');  readln (n);

s:=0;

for i:=1 to n do 

begin

read (A[i]);

if (a[i]>50) and (a[i] mod 10=0) then s:=s+a[i];

end;

for i:=1 to n-1 do

for j:=i+1 to n do

if a[i]<a[j] then begin t:=a[i]; a[i]:=a[j]; a[j]:=t; end;

writeln ('Tong cac phan tu la: ',s);

write ('Day so sau khi sap xep la: ');

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

writeln;

write ('nhap vao so nguyen x= '); readln(x);

for i:=1 to n do if a[i]=x then d:=d+1;

if d<>0 then writeln (x,' xuat hien trong day ',d,' lan')

else writeln (x,' khong xuat hien trong day');

readln;

end.