Claude on Question 1, Oct 1
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 test divisibility by primes up to √91 ≈ 9.54, so I need to check 2, 3, 5, and 7.
Divisible by 2?
91 is odd, so no.
Divisible by 3?
Digit sum = 9 + 1 = 10, which is not divisible by 3, so no.
Divisible by 5?
91 doesn't end in 0 or 5, so no.
Divisible by 7?
91 ÷ 7 = 13 exactly (since 7 × 13 = 91). Yes!
Conclusion
Since 91 = 7 × 13, it has divisors other than 1 and itself, so it is composite, not prime.
[No]
Exact recordShowHideThe model id, the run, the verbatim text with line numbers and its full sha256
- Scored
- answered · correct · format ok
- Received
- 2026-10-01 09:00:12 UTC
- Run
- 20261001T090007Z-857bc9
- Served by
- Claude Platform on AWS · HTTP 200 · finish stop
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- 496 characters · 359 tokens out incl. hidden reasoning · 4.3 s
Highlighted: the last [Yes]/[No] bracket, which is the scored answer (No).
## Step-by-step check
To determine if 91 is prime, I test divisibility by primes up to √91 ≈ 9.54, so I need to check 2, 3, 5, and 7.
**Divisible by 2?**
91 is odd, so no.
**Divisible by 3?**
Digit sum = 9 + 1 = 10, which is not divisible by 3, so no.
**Divisible by 5?**
91 doesn't end in 0 or 5, so no.
**Divisible by 7?**
91 ÷ 7 = 13 exactly (since 7 × 13 = 91). **Yes!**
## Conclusion
Since 91 = 7 × 13, it has divisors other than 1 and itself, so it is composite, not prime.
**[No]**
End of response · 21 lines · 496 characters · sha256 e69d6896f9fce2ab4cdeef5aa5040b45251bc21653b5eba273f382327183796f