Using a spectrometer, a sample was analyzed to have a percent transmittance of 85%. This means that the remainder of the light was absorbed by the sample given in the question.
Now, from the 100% light that has been incident on the sample, if 85% was transmitted, then the percentage of light was actually absorbed by the sample can be found out as:
percentage of light was actually absorbed by the sample=100% - (percentage of light transmitted by the sample)
Therefore, percentage of light was actually absorbed by the sample=100%-85%=15%
Thus, 15% light was actually absorbed by the sample.