Do not calculate 100!
For this 2027 Akuna Capital VidCruiter Video Interview question, the strongest answer turns a large-number problem into a small counting problem. Explain the structure before giving the arithmetic.
Use the wording exactly
Find the number of 0s at the end of 100!. For example, 14! = 87178291200, has two zeros at the end.
Avoid these common mistakes
- Counting only multiples of 10. Many factor pairs come from separate twos and fives.
- Counting multiples of 5 once. The number 25 contributes two factors of 5.
- Leading with a formula. Explain why the formula works before applying it.
- Stopping without a conclusion. State the final count clearly after the arithmetic.
A concise answer framework
A trailing zero requires a factor of 10, which is one 2 paired with one 5. Since 100! contains many more twos than fives, count the fives: floor(100/5) = 20. Multiples of 25 contain an additional factor of 5, so add floor(100/25) = 4. There are no further powers of 5 at or below 100. The answer is 24.
This explanation is compact enough for a timed response while still showing the reasoning that makes the answer defensible.
Practice the complete set
This prompt covers one quantitative task in the Akuna Capital process. OfferTutoring has the complete questions for the verified firm and assessment, helping candidates prepare the full range of question types.
