As long as you can actually walk them through your thought process on how you came up with the answer, I think you're good. But a good interviewer should also

As long as you can actually walk them through your thought process on how you came up with the answer, I think you're good. But a good interviewer should also follow up on questions that can lead to trivia-type answers. For example, if some interviewer ask you "What is the sum of integers from 1 to 100", a valid answer from you could be "Well we learned in school that Gauss figured out this problem at early age, and came up with the answer 5050 - so the answer is 5050" In which case the interviewer has the options of A) Conclude the question, and move onto something else B) Try to get you to expand on this theory - and how Gauss came up with that If he then goes with B, and you start explaining that (1 + 100) + (2 + 99) + ... + (50 + 51) equals 5050, he could ask you to come up with a more general form of this answer - i.e the sum of some arbitrary arithmetic sequence. And if you then go to expand on this, and arrive at the answer that the sum of the original sequence is sum = s(s+1)/2, then that is IMO very good for both parts. The key here is that you actually walk them through the steps, and interact with the interviewer. Maybe they introduce constraints, or new rules. One can take "easy" questions that you've seen thousands of times, and make them into interesting ones, where you spend some time communicating, and showcasing how you solve problems. The point is not to arrive at "the sum is 5050", but rather to monitor how you think, and solve problems, with people around you.