1)
uses crt;
var a,b: integer;
begin
clrscr;
write ('nhap a: '); readln (a);
write ('nhap b: '); readln (b);
if a mod b=0 then writeln (a,' la boi so cua ',b);
if a mod b<>0 then writeln (a,' khong phai la boi so cua ',b);
if b mod a=0 then writeln (b,' la boi so cua ',a);
if b mod a<>0 then writeln (b,' khong phai la boi so cua ',a);
readln;
end.
