Find the solution of the exponential equation \( 16 e ^ { x } = 12 \) in terms of logarithms, or correct to four decimal places. \( x = \) 

Certain radioactive material decays in such a way that the mass remaining after \( t \) years is given by the function 

\( m ( t ) = 100 e ^ { - 0.01 t } \) 

where \( m ( t ) \) is measured in grams. (a) Find the mass at time \( t = 0 \) . Your answer is (b) How much of the mass remains after \( 20 \) years? Your answer is Round answers to \( 1 \) decimal place.