1. The problem statement, all variables and given/known data Suppose you have a 1.4g sample of old charcoal. It produces 0.7 beta decays per minute. How old is the charcoal. Given: 1g of carbon current day has 6.36x1010 atoms of 14C 2. Relevant equations N = Noe-rt N = number of atoms in the sample (current-day) No = original number of atoms (i.e. at time of death) r = decay rate = 1.21x10-4 t = time 3. The attempt at a solution I know that No = 1.4*6.36x1010 = 8.904x1010 r = 1.21x10-4 what I don't understand is what to do with the 0.7 decays per minute. I know I need to solve for N before I can solve for t, but I'm stuck. As soon as I solve for N, it's plug and chug. Any help would be much appreciated!