The ratio of the map is 1cm: 20 km.
On the map, the two cities are 2.5 cm apart. Using the ratio and proportion method one obtains the equation:
[tex] \frac{1 cm}{20 km} = \frac{2.5 cm}{y (km)} [/tex]
y is the measurement in kilometer. Multiplying 20 by 2.5 and dividing by 1. This is by cross multiplication which is a simpler method in evaluating fractions and finding for the unknown. The answer is 50 km.
