And best gets brainliest.
the scale model of a skyscraper being built is 4.2 feet tall.
a) when it is finished, the skyscraper will be 525 meters tall. what scale was used to make the model?
b) the model is made out of a stack of plywood sheets. each sheet is 0.6 inch thick. how many sheets
of plywood tall is the model?

A) 125 meters : 1 foot
The scale is the real skyscraper's height to the model's. 
525 meters / 4.2 ft
125 meters to 1 ft
125:1

b) 84 pieces
The model is 4.2 feet or (4.2 x 12) 50.4 inches tall.
Each sheet is .6 thick
To find how many sheets are used, divide the model's height in inches by the individual thickness of each sheet
50.4/.6
84 pieces

Hope this helps :)