Question

A building has 4 stories that are each 15 feet high. A scale drawing has the height of the building at 5 inches.

Answer 1

Every 1 inch is 12 feet.

Answer 2

1) a 
The building is 4*15 = 60 feet = 720 inches high. The ratio is 720/5 = 144 

2) b 
The ratio is 9/(1/4) = 36. So 1 foot = 12 inches and 12/36 = 1/3 

3) c 
With a ratio of 1:72, a 7.5 inch wingspan represents 7.5*72 = 45 feet 

I hope this helps!