Describe the relationship between the amount of C-15 and time?

As time increases, C-15 (Carbon) decreases. During radioactive decay, the amount of Carbon in a substance undergoes half-lives (A sample could have  a half life of 1002 years, for example.) When that substance ages to that timeframe, it loses half of its mass. Then for the next half-life, it loses half of that new mass, and so on.

because of all the things that happen around the us, many people get into arguments which sadly could get physical, but we should actually make a change for that.