Problem Analysis #4

32.96s
1,741 toks
Problem Statement

Suppose the following limit is given:

limn[0,n](1+20569nx)69ne(67x)dx=pq,\lim_{n\to\infty} \int_{[0,n]} \left(1+\frac{205}{69n}x\right)^{-69n} e^{(-\frac{6}{7}x)}\,dx=\frac{p}{q},

where pp and qq are positive integers which are relatively prime. Find p2qp^2q.

oindent

Ground Truth
70609
Execution Trace
Reasoning Process

[THOUGHT] Let f(x)=(1+20569nx)69ne(67x)f(x) = \left(1+\frac{205}{69n}x\right)^{-69n} e^{(-\frac{6}{7}x)}. As nn \to \infty, we have 20569n0\frac{205}{69n} \to 0. Thus, [ \left(1+\frac{205}{69n}x\right)^{-69n} \approx e^{-\frac{205}{69n}x \cdot 69n} = e^{-205x}. ] Therefore, the integral becomes [ \lim_{n\to\infty} \int_{[0,n]} e^{-205x-\frac{6}{7}x},dx = \lim_{n\to\infty} \int_0^n e^{-(205+\frac{6}{7})x},dx. ] We have 205+67=1435+67=14417205 + \frac{6}{7} = \frac{1435+6}{7} = \frac{1441}{7}. [ \lim_{n\to\infty} \int_0^n e^{-\frac{1441}{7}x},dx = \lim_{n\to\infty} \left[-\frac{7}{1441}e^{-\frac{1441}{7}x}\right]0^n = \lim{n\to\infty} -\frac{7}{1441}e^{-\frac{1441}{7}n} - \left(-\frac{7}{1441}e^0\right) = \lim_{n\to\infty} -\frac{7}{1441}e^{-\frac{1441}{7}n} + \frac{7}{1441}. ] Since limne14417n=0\lim_{n\to\infty} e^{-\frac{1441}{7}n} = 0, we have [ \lim_{n\to\infty} \int_0^n e^{-(205+\frac{6}{7})x},dx = \frac{7}{1441}. ] Thus, p=7p=7 and q=1441q=1441. We need to check if they are relatively prime. 1441=7205+61441 = 7 \cdot 205 + 6. Thus gcd(7,1441)=gcd(7,6)=1\gcd(7,1441) = \gcd(7,6)=1. Then p2q=721441=491441=70609p^2q = 7^2 \cdot 1441 = 49 \cdot 1441 = 70609.

p = 7
q = 1441
print(p**2 * q)
Tool Output
[PYTHON OUTPUT] 70609 [/PYTHON OUTPUT]
Reasoning Process

[THOUGHT] The Python output confirms the calculation 721441=706097^2 \cdot 1441 = 70609.

\boxed{70609}

Final Model Output
70609

Comparative Analysis (P4) (Average across runs)

Avg Time Taken

Deepseek-R1-distill-Qwen-32B (high)
140.9
Deepseek-V3.2
123.2
Gemini-3-Pro-Preview
90.8
GPT-oss-20B (high)
60.4
Solar-Pro-2 (31B)(high)
60.2
Grok-4.1-fast
38.4
HCX-007(high)
31.5
Gemma-3-27B
31.4
Qwen3-30B-A3B-2507
28.9
Llama-VARCO-8B-Instruct
21.3
GPT-5.1 (high)
19.0
Claude-Opus-4.5
16.4
A.X-4.0 (72B)
16.0
EXAONE-4.0.1-32B (high)
3.7

Avg Token Usage

Gemini-3-Pro-Preview
11241.0
Deepseek-V3.2
9874.7
Solar-Pro-2 (31B)(high)
9831.3
GPT-oss-20B (high)
9757.0
Grok-4.1-fast
7671.7
Qwen3-30B-A3B-2507
6266.7
HCX-007(high)
4190.3
Deepseek-R1-distill-Qwen-32B (high)
3984.0
Claude-Opus-4.5
3858.3
A.X-4.0 (72B)
3485.3
EXAONE-4.0.1-32B (high)
3238.3
GPT-5.1 (high)
3067.7
Llama-VARCO-8B-Instruct
2088.3
Gemma-3-27B
1705.7