The radioactive isotope, ¹⁴C does not occur naturally but it is found at constant rate by the action of cosmic rays on the atmosphere. It is taken up by plants and animals and deposited in the body structure along with natural carbon, but this process stops at death. The charcoal from the fire pit of an ancient camp has an activity due to ¹⁴C of 12.9 disintegrations per minute, per gram of carbon. If the percentage of ¹⁴C compared with normal Carbon in living trees is 1.35×10⁻¹⁰%, the decay constant is 3.92×10⁻¹⁰ s⁻¹ and the atomic weight=12.0, what is the age of the campsite?