1. The problem statement, all variables and given/known data Please help me solve this problem... Given T(1/2) of U-235 = 7.04x10^8 yrs (0.7%) T(1/2) 0f U-238 = 4.468x10^9 yrs (99.3%) Calculate percentage of U-235 & U-238 at the time of creation of earth(~4.5 billion years ago) 2. Relevant equations N(t) = No e^(-λt) 3. The attempt at a solution λ(U-235) = 9.84x10^-10 per year λ(U-238) = 1.55x10^-10 Now m confused how to proceed further with percentages...???