const n=10;
var ar:array[1..n] of integer;
a,k,i:integer;
begin
Randomize;
for i:=1 to n do 
 begin
 ar[i]:=random(20)+1;
 write(ar[i]:3);
 end;
writeln;
write('a = ');
readln(a);
k:=0;
for  i:=1 to n do 
 if ar[i] mod a = 0 then k:=k+1;
writeln('k = ',k);
end.

Пример:
 15  2 20 13 12  2  7 14  2  4
a = 3
k = 2