The conversion rate is 1cm to 4km, or 1:4.
Because we know the conversion rate, we can use this ratio to calculate the map distance.
If the distance between the two towns is 28km, then we can use the conversion rate to calculate the distance on the map.
28 / 4 = 7
Therefore, the distance between the two towns on a map is 7cm.
Hope this helped! :)