[zzzan]

How do i find the age of the sample?

[Babcock_Hall]

Hi zzzan,

It is a forum rule (see red link above) that you must show us your attempt first, before we can help you.  Can you think of any equations that you learned in your class?  You can use the graphs that you provided to find an approximate answer, which should agree with one that you calculate.

[zzzan]

Hi zzzan,

It is a forum rule (see red link above) that you must show us your attempt first, before we can help you.  Can you think of any equations that you learned in your class?

sure. the age is half life*no. of years in a half life. 13% puts it at 3 half lives*50 million= 150 million years?

[Babcock_Hall]

That looks OK to me.