3 balls of wool and the way I got the answer was if 4 balls of wool make 8 caps then 2 balls of wool make 4 caps so the answer would be 3 balls of wool because 1 ball of wool makes 2 caps and so 2 balls of wool makes 4 caps and 3 balls of woll makes 6 caps and 4 balls of wool would make 8 caps
