To the nearest tenth of a kilometer, what is the actual distance corresponding to the map distance?

Question

A map has a scale of 1cm : 11km. Two cities are 4.2 cm apart on the map.

Answer 1

Let's set up a proportion using the given ratio of cm to km and then solve for our unknown km (x):

 

1 cm : 11km = 4.2 cm : x km

 

Then let's cross multiply the values in the above ratios of our proportion to get our equation:

 

(1)(x) - (11)(4.2)

 

Now let's solve for x:

 

x = (11)(4.2)

 

x = 46.2 km