As is always the case with Graphics problems, we should read the text to help understand this image. Some questions can be answered without referencing the passage, but it's always easier to read first. And in this case, a single word--"magnification"--helps us understand the image. Those gray triangles marked off by dotted lines are telling us which part of the bar on the left is magnified by the bars moving right.
So, for the first question, the Miocene Epoch isn't in the same bar of the graph as any of the Eras. But looking at the magnification indicators, we can see that the entire rightmost graphic is expanded from the Cenozoic era. So, since the Miocene takes up about 25% of it's bar, it takes up about 25% of the Cenozoic Era of which it is part.
As for the second question, it asks for something about eons, eras, and periods--that puts us in graph 2. We're asking for the beginning of all three, which means we want a line straight across the graph. That's the Cambrian period, which starts the Phanerozoic Eon and the Paleozoic Era.
Prepare with Kaplan and save $150 on a course!