1. The problem statement, all variables and given/known data 0ops.. The title should read solving logs.. Mod note: Fixed. the original dosage contains 280 MBq of Iodine-131. If none is lost from the body, then after 6 hr there are 274 MBq of iodine-131. What is the half life of iodine I-131? 2. Relevant equations Logcx=y 3. The attempt at a solution I tried to put 274=280(1/2)^t/6 in and solve for t. But now I know it can't be right because it is not halving every 6 hrs.. However I don't know how you would figure it out. Can someone give me a hint?