Given the task definition and input, reply with output. In this task you're given a question and you have to paraphrase the question to create the output question while retaining the meaning of the original question.

Three particles of mass 1kg, 2kg and 3kg are placed at the corners A, B and C respectively of an equilateral triangle ABC of edge 1m. How do I find the distance of their centre of mass from A?
If 8 equal masses m are placed at the vertex of the cube what is the net force at the centre of cube when unit mass m is placed at the centre?