using Mongo please help

1. Describe how you can export your MongoDB collections and how you can import data into your MongoDB database?
2. What two formats you can export your MongoDB collections?
3. On Mongosh, what command is used to delete one document? Give an example as your answer.
4. On Mongosh, what command is ued to delete multiple document? Give an example as your answer.
5. On Mongosh, what command is used to update one document? Give an example as your answer.
6. On Mongosh, what command is ued to update multiple document? Give an example as your answer.
7. Suppose when you issue a command to update one document, but somehow there are multiple documents meet your update condition, what will happen?
8. On Tutorial 14, it shows how to use Increment to update an integer property by increasing its value. Suppose now we want to decrease the value of an integer property. Is there a separate command for this? Why or why not?