Solve the Problem $P = 100 e ^ { - 0.15 n }$

Short Answer

Solve the problem.
-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?