SOTI Software Developer Co-Op interview questions

Brain teaser question : If you have 3 labeled boxes with labels apple , orange and mixed, how can you determine which label are correct for which box if all current labels are miss placed labels ?

The first few questions had to do with Strings and Linked Lists, just general data structures questions. Then they asked 2-3 questions, something along the lines of how would you find the pairs (with a dictionary) and how would you find the missing number. It's honestly just annoying but its your basic code interview questions. Although, I don't think they are looking for your "thought process" they just want to know if you can get the answer