1∶x= 1∶4000000

x=4000000

Let the distance on the map be y cm.

y∶4000000= 1∶6000000

y=4000000/6000000

y=2/3

A: It should be 2/3 cm.

600 m =60000 cm

Scale: 2∶60000= 1∶30000

Assume that the actual distance is x cm.

4∶x= 1∶30000

x= 120000

120000m =1200m

The actual distance from Wang Qiang's home to the post office is1200m.