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
3 answers
I agree.
Thank you very much!
You're welcome.