Gemini on Question 1, Sep 19

Is 91 a prime number? Think step by step and then answer "[Yes]" or "[No]".

To determine if 91 is a prime number, we can check if it is divisible by any prime numbers smaller than its square root (the square root of 91 is approximately 9.5, so we need to check the primes 2, 3, 5, and 7).

1.Check 2: 91 is not an even number (it ends in 1), so it is not divisible by 2.
2.Check 3: The sum of the digits is 9 + 1 = 10. Since 10 is not divisible by 3, 91 is not divisible by 3.
3.Check 5: 91 does not end in 0 or 5, so it is not divisible by 5.
4.Check 7: Let's divide 91 by 7.
7 × 10 = 70
91 - 70 = 21
7 × 3 = 21
Therefore, 7 × 13 = 91.

Since 91 can be divided evenly by 7 and 13, it has factors other than 1 and itself. Therefore, it is a composite number, not a prime number.

[No]

sha256 3dfe5b1a3436… · 22 tokens in · 648 out · 5.6 s · via Google · stopped on its own

Sep 19, the whole day Question 1, every day

Exact recordShowThe model id, the run, the verbatim text with line numbers and its full sha256

Model: google/gemini-3.1-pro-preview
pinned google/gemini-3.1-pro-preview-20260219; alias resolved to google/gemini-3.1-pro-preview-20260219 at 2026-09-19 09:00:04 UTC (matches the pin)
Date: 2026-09-19 · run 20260919T090005Z-86161c · scorer v1
Scored: answered · correct · format ok
sha256: 3dfe5b1a3436c81280d72c9f66dfc746716d6b38ad2aa5418f1f5406b046974e
Permalink: https://modeldrift.watch/r/2026-09-19/D1/google/gemini-3.1-pro-preview/

Scored: answered · correct · format ok
Received: 2026-09-19 09:00:18 UTC
Run: 20260919T090005Z-86161c
Served by: Google · HTTP 200 · finish stop
Size: 741 characters · 648 tokens out incl. hidden reasoning · 5.6 s

Highlighted: the last [Yes]/[No] bracket, which is the scored answer (No).

To determine if 91 is a prime number, we can check if it is divisible by any prime numbers smaller than its square root (the square root of 91 is approximately 9.5, so we need to check the primes 2, 3, 5, and 7).
1. **Check 2:** 91 is not an even number (it ends in 1), so it is not divisible by 2.
2. **Check 3:** The sum of the digits is 9 + 1 = 10. Since 10 is not divisible by 3, 91 is not divisible by 3.
3. **Check 5:** 91 does not end in 0 or 5, so it is not divisible by 5.
4. **Check 7:** Let's divide 91 by 7. 
   7 × 10 = 70
   91 - 70 = 21
   7 × 3 = 21
   Therefore, 7 × 13 = 91.
Since 91 can be divided evenly by 7 and 13, it has factors other than 1 and itself. Therefore, it is a composite number, not a prime number.
[No]

End of response · 14 lines · 741 characters · sha256 3dfe5b1a3436c81280d72c9f66dfc746716d6b38ad2aa5418f1f5406b046974e