Service
Correct! Whenever you head out to get your hair cut you’re having a service performed.  Hopefully you look happier than this guy!
Is a haircut an example of a GOOD or a SERVICE?
Incorrect. When you get your hair cut you’re getting a SERVICE in exchange for money, in this example, the service is the haircut.
Next
Good
Is a brand new sports car a GOOD or a SERVICE?
Correct! This shiny new car is an example of a "Good" that you purchase!
Incorrect. While the car salesman who might sell you this vehicle is performing a service the actual GOOD that you leave with would be the car.
Correct! In the last question you may have correctly identified that a car is a GOOD.  The tires you put on the car are ALSO goods.  The SERVICE is the people who put them on your car for you.
Is a new tire for a car a GOOD or a SERVICE?
Incorrect. Buying a new tire for your car is NOT a service it is a good.   If you paid someone else to put it on for you, that is a SERVICE.  The tire will always be the GOOD.
Is a box of cereal a GOOD or a SERVICE?
Correct! A box of cereal is a GOOD
Incorrect! A box of cereal is a GOOD, not a SERVICE
Is mowing the lawn a GOOD or a SERVICE?
Correct! Having someone mow your lawn is a service. Mayber your parents have YOU mow the lawn.
Incorrect. If the question had asked about the lawn mower/lawn tractor it would have been considered a GOOD.  The action of mowing the lawn is a SERVICE. Have your parents ever asked YOU to mow the lawn?
Is tree removal a GOOD or a SERVICE?
Correct! This guy is clearing trees, which is a SERVICE.
Incorrect. This guy is clearing trees, which is a SERVICE.