# FNGR 1 | Lesson 2 | Practice (Half-Life) Solutions

1. He will have 32 mg 5.7 hours after 8:00 am or at approximately 1:45.
He will have $$64(.5)^\frac{4}{5.7} ≈ 39.3$$;  $$39.3$$ mg left at noon.
He will have $$64(.5)^\frac{12}{5.7}≈14.9$$;  $$14.9$$ mg left at 8 pm.
He will have $$64(.5)^\frac{18}{5.7}≈7.2$$; $$7.2$$ mg left at 2 am.
2. Equation $$A = 64(.5)^\frac{t}{5.7}$$