Exercise 2.10- ROS Navigation

Which folder is the gmapping_demo.launch located at?
Another basic question on how to run the launch file. Is it
roslaunch gmapping_demo.launch

Hello @rojiroy,

As you can see in the instructions for Exercise 2.1, it asks you to execute the following command:

roslaunch turtlebot_navigation_gazebo gmapping_demo.launch

This already gives you the structure of the command you need to use in order to run the launch file and also, it tells you that the gmapping_demo.launch file is inside the turtlebot_navigation_gazebo package.