Tow masses, (m1 = 600g and m2 = 150g) are hanging from a meter stick. m1 is located at the 10cm mark and m2 is at the 7cm mark. If the center-of-mass of the combination (made up of the meter stick and the two point masses) is at the 30-cm mark of the meter stick, what is the mass of the meter stick?
Note: The solution is 300g