### Instruction: The distance between two cities on a map is 4 centimeters. If the scale is 0.5 cm:1 km, how many kilometers apart are the actual cities?### Response: To solve this problem, I need to use the scale factor to convert from map distance to real distance.
The scale factor tells me that every 0.5 cm on the map corresponds to 1 km in reality.
So, to find the real distance, I need to multiply the map distance by the ratio of 1 km to 0.5 cm.
This is equivalent to dividing the map distance by 0.5 cm and then multiplying by 1 km.
So, I have 4 cm / 0.5 cm * 1 km = 8 km.
Therefore, the actual cities are 8 kilometers apart.