This problem involves a set of figures, each with its own weight. To solve the problem, you need to express the weight of the figure that is only present on the left side of the scale in terms of the other weights. There is only 1 answer option that has the same relation. In this case you would say: 2a + 1b = 2a + 1c => 1b = 2a - 2a + 1c. There is only one answer option that gives the same relation