Interviewers are trying to assess whether "you can count" - you don't need to be a math whiz to be a banker, but you do need to be comfortable with numbers and calculations in Excel.
So if you haven't majored in something quantitative or your work experience is all journalism-related, you'll want to prepare a few examples of your analytical abilities.
Even if you have had finance or analytical experience, you're still likely to be asked about your analytical skills - they want to test your communication abilities and make sure you can express abstract concepts clearly.
These questions are also a good chance to bring up any independent study of finance you've done, which will help your case once again.
1. I see you've done mostly journalism and research internships before. Can you discuss your quantitative skills?
You should respond by discussing specific times when you had to analyze numbers and/or use logic. Good examples might include: your personal portfolio, any math/science classes you've taken, any type of budgeting process you've been through, any type of research you've done that involved numbers.
2. In your last internship, you analyzed portfolios and recommended investments to clients. Can you walk me through your thought process for analyzing the returns of a client portfolio?
The key is to break everything down into steps and be very specific about what you did. So you might say that "Step 1" was getting a list of when they bought each investment and how much they invested / how many shares they acquired; "Step 2" was finding a list of when they sold each investment, and what they sold them for; and "Step 3" was aggregating this data over the years in-between for each investment to calculate the compound return.
3. Can you tell me about the process you used to analyze space requirements for the building designs you worked on this past summer?
Similar to the reasoning above, break it into steps and start by discussing how you made the initial estimates, then how you refined them and made them more exact over time while staying within budget and collaborating with your team.
4. You've been working as a lawyer for the past 3 years - what initiative have you taken on your own to learn more about finance?
You should either present a list of self-study courses or certifications such as the CFA that you've obtained, or speak about your own work studying independently from textbooks, self-study courses and other sources. Be conservative with how much you claim to know - re-iterate that you're "not an expert" but that you have taken the initiative to learn something on your own.
5. You were an English major - how do you know you can handle the quantitative rigor required in investment banking?
Combine the answers to questions #1 and #4 for this one - the key is to use specific examples rather than just saying, "I got a high math SAT score!" Personal financial experience, classes, self-study courses and independent study work well.
6. Can you tell me about a time when you submitted a report or project with misspellings or grammatical mistakes?
It's unrealistic to claim that you're perfect and have never done this. Instead, briefly mention a time when you made a careless mistake and then spend the majority of time in your answer discussing what you learned and how you improved, citing another specific example of how you improved the second time around.
7. What's the most number of classes you ever took at once and how well did you do in each of them?
Once again, it's best to point to something specific - "During my junior year, I was taking 5 classes at once as well as working part-time and running my business fraternity - and I still got A's in all of them."
Not everyone has a perfect answer, but try to think about the most stressful time in your academic life and use that as a reference for your answer.
State the "challenge" first, then how you responded, and then how well you did.
8. How well can you multi-task?
In keeping with our theme of specificity, give a concrete example of a time when you were working on multiple projects at the same time - work, school, or activities work equally well for this one. Also emphasize that despite the considerable demands, you pulled off everything successfully. Anything involving teamwork or collaboration is also good to use in this response.
9. Have you ever worked on a project or report that was shown to a large number of people?
A journal, student publication or anything similar could be good to mention here, as could anything shown to a client or multiple clients in your work experience or in an internship.
If you don't have something like this, the best approach is to come as close possible by saying, for example, "I haven't worked on a widely circulated publication, but I did work on such-and-such..., which required that all the details were perfect and that there were no mistakes..."
You could even cite lab or medical work - even if it wasn't widely circulated, anything requiring strong attention to detail suffices.