The diagram below shows nine circles each tangent to all its neighbours. One of the circles is labelled 1. The remaining circles are to be labelled with 1, 2, 3, 3, 3, 4, 4 and 4, such that no two tangent circles have the same label. In how many different ways can this be done? This is the diagram.
Is there a formula to solve these types of questions? If yes, then please share it. It would be of great help.
Sorry if this question turned out to be very easy. I just want to know a formula to solve these questions.