What is the scale if: a) 3.2 cm on the map correspond to 4 km in the actual distance? b) 50 km in the actual distance correspond to 4 cm on the map? c) 3 cm on the map correspond to 120 km in the actual distance?

a) 1 : 125000

3.2cm on map represent 4km in actual distance

therefore, divide 4 by 3.2 to get how much 1cm represents in actual distance:

4/3.2 = 1.25

1cm --> 1.25km

now convert 1.25 km to cm to cancel the units and get the scale

1cm = 1.25 x 100000

1 : 125000

b) 1 : 1250000

50/4 = 12.5km

1cm on map represents 12.5 km in actual distance

so convert it in cm to find the scale

12.5 x 100000 = 1250000

c) 1 : 4000000

120/3 = 40km

1 cm on map represents 40km in actual distance

convert 40km to cm

40 x 100000 = 4000000