Question

sunlight passing through a window pane of glass is decresed by 2.9%. How many panes of glass will reduce the sunlight by at least 64%?

Answer 1

Ok each panel is going to decrease the light of the previous panel by 2.9%, so you would start with 100% light. So the first panel will let 100 x (100(.029)) of light through. Once you get that answer you do the same calculation but you use that answer instead of 100. Keep doing that on your calculator until you get to 64% and count how many panels you needed.