Question

Carol is studying the eating habits of a pack of wolves. For this particular pack, it is considered unusual if a wolf eats less than 4 pounds, or more than 9 pounds, of meat per day. Carol keeps a record of all unusual eating incidents.

Which set describes the amount of food a wolf must eat to qualify as “unusual”?

Answer 1

(0,4) u (9, infinity)

why? you want to use parentheses because it says "less than" More than" not "4 or less" which would mean you use brackets because that includes the number

Answer 2

(-∞, 4) ∪ (9, ∞)

Explanation:

Let x represents the amount of food ( in pounds ) as unusual eaten by wolves,

Since, for considering the amount of food as unusual,

Amount of food < 4 pounds or amount of food > 9 pounds,

⇒ x < 4 or x > 9

⇒ ( -∞, 4 ) or ( 9, ∞ )

⇒ ( -∞, 4 ) ∪ ( 9, ∞ )

Which is the required set that describes the amount of food a wolf must eat to qualify as “unusual”.

Hence, third option is correct.