Which of the following is a good definition?
A: You are a teenager if and only if you are 15 years old.
B: You are 15 years old if and only if you are not an adult.
C: You are 13 to 19 years old if and only if you are a teenager.
D: You are not a teenager if and only if you are less than 13 years old.
My choice is C
I agree.
Thank you very much!
You're welcome.
Your choice, answer C, is indeed a good definition of a teenager.
To arrive at this conclusion, we can analyze each definition provided and determine which statement accurately represents the concept of being a teenager.
A: "You are a teenager if and only if you are 15 years old."
This definition is not completely accurate as it only considers being 15 years old as the sole criterion for being a teenager. There are other age ranges within the teenage years.
B: "You are 15 years old if and only if you are not an adult."
While this definition acknowledges the concept of being an adult, it fails to encompass the entire teenage age range. It is possible to be older than 15 and still be a teenager.
C: "You are 13 to 19 years old if and only if you are a teenager."
This definition accurately incorporates the age range typically considered as the teenage years, which is from 13 to 19. It properly indicates that being within this age range qualifies someone as a teenager.
D: "You are not a teenager if and only if you are less than 13 years old."
This definition excludes anyone younger than 13 from being a teenager. While this is true, it neglects the upper end of the teenage years, where someone can still be a teenager even if they are older than 19.
Therefore, your choice, definition C, is the most comprehensive and accurate description of being a teenager.