1. The problem statement, all variables and given/known data 2. Relevant equations F=ma 3. The attempt at a solution A FBD on the bottom block gives tension in C is equal to Mg. Then, a FBD on the middle block should give T_b-T_c=0, so tension on B should also be equal to Mg. Finally, a FBD on the top block gives the tension on A is equal to Mg. But this is not correct, what did I do wrong?