The actual distance will be 12 km.
Explanation:
The scale of the map is 1:250000
1 cm in the map represents 250000 cm.
250000cm=2500 m=2.5 km
the measurement in the map is 4.8 cm
since 1 cm represents 250000 cm or 2.5 km
The actual distance represented by 4.8 cm on the map = 4.8*250000 cm =1,200,000 cm=12000 m=12 km
