Interviewing at consultancy firms for the graduating class of 2019 seems to be well underway, if my inbox is any judge. Over the holiday period I had a number of requests for help. The most popular topic – maths. Here are my answers to a couple of the questions posed.
Can I use a calculator? Almost certainly, No. The type of maths problem encountered in a quantitative test or case study is typically one of percentages or multiplication. The answer usually doesn’t have to be exact. A good estimation that is not egregiously wrong will suffice. At this level, you’d be expected to do the sums without the support of a calculator. (That said, I have heard of calculators being supplied at the interview: but if not don’t whip yours out…)
Can I use pencil and paper instead? In a quant test, Yes. In a case study interview, Depends. Depends on what? Again, the level of difficulty in most examples is equivalent to high school maths. You should be able to do basic business calculations – return on investment, earnings growth, market share – in your head. But if you think you’ll get it wrong, it is far better to say – “Do you mind if I take a moment to work this out?” and pick up the pencil in front of you (which you’ve brought, along with some paper, to the interview), look the interviewer in the eye for a sign of agreement, and proceed. She might raise an eyebrow, but provided you get the correct answer and the rest of the case goes smoothly, it won’t be counted against you.
The whole point, of course, is to replicate the experience of a consultancy project. When the client asks you “By the way, what’s the impact on X if we reduce the cost of Y by Z%?” you’re expected to come up with an off-the-cuff approximation (although you may also qualify your answer by saying you’ll check that and revert.)
And please, don’t send me examples of the brain teasers you’ve been set and ask for help solving them…