To answer this item, we are to convert the measurement written in km to meters.
(72 km)(1000 m / 1 km) + 200 m = 72200 m
(48 km)(1000 m/ 1 km) + 600 m = 48600m
Then, subtracting will give us an answer of 23600m which when converted back to kilometres will give us an answer of 23 km 600m.