Hint: after your initial weighing, tape some of the balls together (with weightless tape). Bigger hint, label the balls: aaa aab aba abb baa bab bba bbb caa ca

Hint: after your initial weighing, tape some of the balls together (with weightless tape). Bigger hint, label the balls: aaa aab aba abb baa bab bba bbb caa cab cba cbb.