This is a proportion question. We can express this as an equation where the answer is x:
= 
From there, you can just cross-multiply and divide to get:
A tenth of 250 is 25, so this is roughly
or 
, so it'll be approximately 1.7 inches on the map.
From there, you can just cross-multiply and divide to get:
A tenth of 250 is 25, so this is roughly
