The scale of a map is 2cm to 1km. what is the distance between town "a" and town "b" in km when the distance is 20cm

Answer 1

if 2 cm represents 1km
then 1 cm represents 1/2 km
and 20 cm represents 20(1/2) km or 10 km

or

2/1 = 20/x
cross multiply:
2x = 20
x =10

Answer 2

If the scale of map is 2cm to 1km, what is the ground distance if the distance between two town is to 1ocm