Ineed with this problem it is 30/90=1/x

Which equation matches the graph shown ?

Miranda is braiding her hair.then she will attach beads to the braid.she wants 1_3 of the beads to be red.if the greatest number of beads that will fit on the braid is 12,what other fractions could represent the part of the beads that are red?

How do you determine whether a relationship represented as as graph is linear or nonlinear