You cannot open part10 on its own. You need every preceding part (1 through 9) and any subsequent parts in the same folder.
The software recognizes the sequence and automatically pulls data from all the parts (including your part10 ) to recreate the original game folder. A Quick Warning City.Bus.Manager.v1.0.7.0.part10.rar
You generally only need to right-click Part 1 and select "Extract Here" using a program like WinRAR or 7-Zip . You cannot open part10 on its own
To make large games easier to upload and download, they are often split into smaller "parts." You have the 10th segment of that set. City.Bus.Manager.v1.0.7.0.part10.rar