“what is the amount of material G and material H used in each unit of product Y?“ What we’re given isn’t precise enough. In order to know how many kg of G and H the company has used for product Y shouldn’t we be given how many units of Y it has produced? It could’ve just as well produced 50 Ys and 65 Xs which in this case would change the amount of kg of G & H. But since we are just given the two figures (100 & 90) on the Y axis and nothing else along the line, the question is asking us to assume that we’ve only produced Ys…….. although with this graph there is absolutely no indication that, this is the case. Unless I am reading the question wrongly, they should really stop doing that, because then all the answers are wrong.