The amount of a radioactive substance remaining after t years is given by the function LaTeX: f\left(t\right)=m\left(0.5\right)^{ \frac{t}{h}}f ( t ) = m ( 0.5 ) t h, where m is the initial mass and h is the half-life in years. Cobalt-60 has a half-life of about 5.3 years. Which equation gives the mass of a 50 mg Cobalt-60 sample remaining after 10 years, and approximately how many milligrams remain?