(Solved): A mass of 200 grams of a particular radioactive substance decays according to the function \( m(t)= ...

A mass of 200 grams of a particular radioactive substance decays according to the function \( m(t)=200 e \quad-\frac{t}{750} \) \( t>0 \) measures time in years. When does the mass reach 25 grams? The mass reaches 25 grams after \( \mathrm{t}= \) years. (Round to the nearest whole number as needed.)