Additionally, I've uploaded the passage this comes from; however, it doesn't seem necessary to answering this question. But if you are interested click it.

ANSWER:

Here is the answer they have: click here please.

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Okay so I just need

**clarification**for this question!

I understand how to use snell's law in this situation, but it is time consuming to write all this down.

so n1 = index of refraction of air correct, so n1 and n4 are the same, because n1 and n4 are both air?

n2 = crown glass, and n3 = flint glass?

Is there a simpler way to do this, because overall this seems like it could be time consuming... is there a generalized rule for this situation?

Thanks!