Carbon dating presumes that, as long as a plant or animal is alive, the proportion of its carbon that is 14C is constant.
The amount of 14C in an object made from harvested
plants, like paper, will decline exponentially according to
the equation A= 4e
-0.00012131, where A represents the
amount of 14C in the object, A. represents the amount of
14C in living organisms, and t is the time in years since the
plant was harvested. If an archeological artifact has 40%
as much 14C as a living organism, how old would you
predict it to be? Round to the nearest year.