Claude on Question 1, Sep 18
Is 91 a prime number? Think step by step and then answer "[Yes]" or "[No]".Step-by-step check
To determine if 91 is prime, I need to test divisibility by all primes up to √91 ≈ 9.54, so I check 2, 3, 5, and 7.
Divisible by 2?
91 is odd → No.
Divisible by 3?
Digit sum: 9 + 1 = 10, which is not a multiple of 3 → No.
Divisible by 5?
91 doesn't end in 0 or 5 → No.
Divisible by 7?
7 × 13 = 91 → Yes!
Conclusion
Since 91 = 7 × 13, it has divisors other than 1 and itself, so it is composite.
[No]
Exact recordShowHideThe model id, the run, the verbatim text with line numbers and its full sha256
- Scored
- answered · correct · format ok
- Received
- 2026-09-18 09:00:30 UTC
- Run
- 20260918T090022Z-92b6f7
- Served by
- Claude Platform on AWS · HTTP 200 · finish stop
- Size
- 456 characters · 335 tokens out incl. hidden reasoning · 4.7 s
Highlighted: the last [Yes]/[No] bracket, which is the scored answer (No).
## Step-by-step check
To determine if 91 is prime, I need to test divisibility by all primes up to √91 ≈ 9.54, so I check 2, 3, 5, and 7.
**Divisible by 2?**
91 is odd → No.
**Divisible by 3?**
Digit sum: 9 + 1 = 10, which is not a multiple of 3 → No.
**Divisible by 5?**
91 doesn't end in 0 or 5 → No.
**Divisible by 7?**
7 × 13 = 91 → **Yes!**
## Conclusion
Since 91 = 7 × 13, it has divisors other than 1 and itself, so it is composite.
**[No]**
End of response · 21 lines · 456 characters · sha256 1f0d6961ebf54826e419e60a23b4870981d349fa9ca39b0f179755d40ceddf2c