After asking my own question on half-lives and radioactive decay despite having read the library article on Radioactive Decay, I felt that I should post a less formal, more in-depth explanation of how to actually solve the equations.

There are two primary equations that I use when dealing with standard radioactive decay.
1. N=N₀e^-k*t
2. r=ln2/k

N represents the final amount remaining.
N₀ represents the initial amount.
e is the standard variable...