Question 4
Tom has a collection of $13$ snakes, $4$ of which are purple and $5$ of which are happy. He observes that
• all of his happy snakes can add,
• none of his purple snakes can subtract, and
• all of his snakes that can’t subtract also can’t add.
Which of these conclusions can be drawn about Tom’s snakes?
• all of his happy snakes can add,
• none of his purple snakes can subtract, and
• all of his snakes that can’t subtract also can’t add.
Which of these conclusions can be drawn about Tom’s snakes?