The amount of a radioactive substance remaining after t years is given by the function , where m is the initial mass and h is the half-life in years. Iron has a half-life of 2.7 years. Which equation gives the mass of a 200 mg iron sample remaining after t years, and approximately how many milligrams remain after 12 years? ; 2.6 mg
f(t)=2.7(0.5)t; 0.0007 mg
f(t)=200(0.5)t; 0.05 mg
; 9.2 mg