PLEASE HELP SO LOST!! WILL GIVE BRAIN THING IF U HELP WITH ALL 4 Questions, PLEASE HELP 4 PARTS NOT A TEST ITS HOMEWORK!
No need to show your work!!

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

Acircle has a circumference of 2 pi cm. which statement about the circumference and area is true? a comparison of the area and circumference is not possible since the area cannot be determined. the numerical values of the circumference and area of the circle are equal. the numerical value of the circumference is greater than the numerical value of the area. the numerical value of the circumference is less than the numerical value of the area.

At a sale this week, a desk is being sold for $213. this is a 29% discount from the original price. what is the original price?