i have a tricky question here, i hope am putting it in the correct section.

the intensity (I) of a beam of light after passing through a material is given by the formula ( i did it as an attachment so look at it please)

where k is the initial intensity

T is the thickness of the material in cm

c is the absorbtion constant

if the value of c = 0.0101, at what depth will a vertical beam of light be reduced to 50% of its initial intensity.