Question 98283
3 DIFFERENT WEIGHING SHOULD DO IT.
5 & 5 FOR THE FIRST WEIGHING. THE HEAVIEST 5 CONTAINS THE BAD STACK.
DIVIDE THIS 5 INTO 2 SETS OF 2 EACH. THE HEAVIEST SIDE CONTAINS THE BAD STACK.
(WORST CASE)
DIVIDE THE HEAVIEST PAIR AND WEIGH THEM INDIVIDUALLY THE HEAVIEST WILL SHOW UP.