Question

The 14C activity of some ancient Peruvian corn was found to be 10 disintegrations per minute per gram of C. If present-day plant life shows 15 dpm/g, how old is the Peruvian corn? The halflife of 14C is 5730 years.

Answer 1

$$A=A_0\cdot 2^{\frac{t}{T}} \\ ​ 15=10\cdot 2^{\frac{t}{5730}} ​\\ t=3350\ years$$