CHemistry
posted by Devin BOutte .
Given that the half life of c 14 is 5,700 ,use the method c 14 dating to determine the age of a fossil if it has 25% of c 14 compared to living specimen.

k = 0.693/t_{1/2}
Calculate k and substitute into the following:
ln(No/N) = kt.
Use No = 100
N = 25
k from above.
Solve for t. I estimated about 11,000 years but you need to calculate it more accurately and remember the number of significant figures. 
I don't really now this, but I suggest looking on google because they have many many answers and if you find out what this is then let me know!