AAMC Physics Q pack #95

Here is the question (it is question #95): A 0.5 kg uniform meter stick is suspended by a single string at the 30 cm mark. A 0.2 kg mass hangs at the 80 cm mark. What mass hung at the 10 cm mark will produce equilibrium?

The answer choices are: A. 0.3 kg B. 0.5 kg C. 0.7 kg D. 1.0 kg (this is the answer)

I understand the torque equation and how to use it. I also understand the relationship between this equation and relating it to equilibrium. However, where I am getting lost, is that I'm having a difficult time understanding what the set up of this system actually looks like. Without understanding this, I can't understand where the fulcrum (point of suspension would be), and which masses are on the same side of the fulcrum, and which are not. Is anyone able to help?