Answer:
The scale is : 1 in : 2.5 ft
Explanation:
An architect notices that the scale on a blueprint he is using has been torn off.
However, he sees that a 12.5-ft. wall that has been built is 5 in. long on the blueprint.
Let the scale be x
So, scale = x = 12.5/5 2.5
5/12.5 =1/x
So, the answer is : 1 in : 2.5 ft
Hope this helps, have a nice day! :D