During interphase (1), chromatin is in its least condensed state and appears loosely distributed throughout the nucleus. Chromatin condensation begins during prophase (2) and chromosomes become visible. Chromosomes remain condensed throughout the various stages of mitosis (2-5).
Balanced forces are forces that are equal in force but opposite sides. Mary would need to push on the opposite side of Trey with the same force of 30N. (I provided a photo to visualize)