Answer: 25%
Explanation: Â
1. Transmittance, T= P/P0 Â
Where P = light exiting the cell
      P0 = light entering the cell
Therefore %T =  P/P0 ×100
      = 50/200×100
=25%
2. Absorbance, A= -log(T)
But T= 0.25
Therefore A= -log(0.25)
         = 0.6020