The shortcut is the real test
This 2027 Akuna Capital VidCruiter Video Interview prompt looks computational, but multiplying out 100! would miss the point. The interviewer is testing whether you can identify the scarce factor behind every trailing zero.
The exact question
Find the number of 0s at the end of 100!. For example, 14! = 87178291200, has two zeros at the end.
What a strong explanation notices
- Each trailing zero comes from a factor of 10. A 10 is formed by pairing a 2 with a 5.
- Twos are plentiful. The number of complete pairs is therefore controlled by the number of factors of 5.
- Some multiples contribute more than one 5. Multiples of 25 must be counted again.
- The method generalizes. The same floor-division pattern works for larger factorials.
Build the count
Count the multiples of 5 in 100!: floor(100/5) gives 20. Then count the extra factor of 5 contributed by every multiple of 25: floor(100/25) gives 4. Higher powers of 5 exceed 100, so the total is 20 + 4 = 24.
In a timed response, state the factor-pair insight first, show the two floor divisions, and finish with the result. That sequence demonstrates both correctness and communication discipline.
Prepare beyond one numerical prompt
This is one Akuna Capital interview question. OpenInterview has the complete questions for the verified firm and assessment, supporting practice across quantitative and verbal prompts.
