Answer
The nuts on the lower side of the highest walkway experience a weight of 3M.
Work Step by Step
Just as they did before, the nuts will experience the full weight of the walkways, M, pulling down on it. This time, however, the nuts will experience triple the weight because there is another set of metal rods that allow the weight to pull on the nuts even further. The nuts on the top experience the weight from each and every walkway , 3M.