Gemini on Question 1, Sep 10

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 (which is roughly 9.5).

Step 1: Check divisibility by 2.
91 does not end in an even number (0, 2, 4, 6, or 8), so it is not divisible by 2.

Step 2: Check divisibility by 3.
The sum of the digits of 91 is 9 + 1 = 10. Since 10 is not divisible by 3, 91 is not divisible by 3.

Step 3: Check divisibility by 5.
91 does not end in a 0 or a 5, so it is not divisible by 5.

Step 4: Check divisibility by 7.
Let's divide 91 by 7:
7 × 10 = 70
91 - 70 = 21
7 × 3 = 21
So, 7 × 13 = 91.

Since 91 can be divided evenly by 7 and 13 (in addition to 1 and itself), it is a composite number, not a prime number.

[No]

sha256 c4e412f1bd8e… · 22 tokens in · 867 out · 7.3 s · via Google · stopped on its own

Sep 10, 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; no alias snapshot recorded that day
Date: 2026-09-10 · run 20260910T221001Z-bb5bd1 · scorer v1
Scored: answered · correct · format ok
sha256: c4e412f1bd8e2e216fda8fb53f9a0eff21550442c7b08f48e9792c877782f80b
Permalink: https://modeldrift.watch/r/2026-09-10/D1/google/gemini-3.1-pro-preview/

Scored: answered · correct · format ok
Received: 2026-09-10 22:10:16 UTC
Run: 20260910T221001Z-bb5bd1
Served by: Google · HTTP 200 · finish stop
Size: 727 characters · 867 tokens out incl. hidden reasoning · 7.3 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 (which is roughly 9.5). 
Step 1: Check divisibility by 2.
91 does not end in an even number (0, 2, 4, 6, or 8), so it is not divisible by 2.
Step 2: Check divisibility by 3.
The sum of the digits of 91 is 9 + 1 = 10. Since 10 is not divisible by 3, 91 is not divisible by 3.
Step 3: Check divisibility by 5.
91 does not end in a 0 or a 5, so it is not divisible by 5.
Step 4: Check divisibility by 7.
Let's divide 91 by 7:
7 × 10 = 70
91 - 70 = 21
7 × 3 = 21
So, 7 × 13 = 91. 
Since 91 can be divided evenly by 7 and 13 (in addition to 1 and itself), it is a composite number, not a prime number.
[No]

End of response · 21 lines · 727 characters · sha256 c4e412f1bd8e2e216fda8fb53f9a0eff21550442c7b08f48e9792c877782f80b