Radiation of wavelength 290 nm passed through 1.0 mm of a solution that contained an aqueous solution of the  amino acid tryptophan at a concentration of 0.70 mmol dm-3. The light intensity is reduced  to 60% of its initial value. Calculate the absorbance and the molar absorption coefficient of tryptophan at 280 nm. What would be the transmittance through a cell of thickness 3.0 mm?