Problem #7

You are given three parallel panes of glass. Each pane will transmit 70%, reflect 20%, and absorb 10% of the light that falls on it. If a light source is placed on one side of the three panes, what is the total percentage of light that passes through to the other side?

For example, if a beam of light follows the path in Figure 1, .7 x .7 x .7 of the light would be transmitted, but if a beam of light followed the path shown in Figure 2, .7 x .7 x .2 x .2 x .7 of the light would be transmitted.

The problem is to find the TOTAL amount of light transmitted.