Write the Word or Phrase That Best Completes Each Statement $$P = 100 e ^ { - 0.15 n }$$

Short Answer

Write the word or phrase that best completes each statement or answers the question.
-If a single pane of glass obliterates 15% of the light passing through it, then the percent P of light that passes through n
successive panes can be approximated by the equation $$P = 100 e ^ { - 0.15 n }$$ How many panes are necessary to block at least 50% of the light?