Problem Analysis #4

4.38s
3,432 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] To solve this limit problem, I need to evaluate the integral and then take the limit as ( n ) approaches infinity. The integrand resembles the form of an exponential function multiplied by a term that looks like a limit definition of the exponential function. I recall that: [ \lim_{n \to \infty} \left(1 + \frac{a}{n}x\right)^n = e^{a x}. ] Using this, the term (\left(1 + \frac{205}{69n}x\right)^{-69n}) can be rewritten as: [ \left(1 + \frac{205}{69n}x\right)^{-69n} = \left[\left(1 + \frac{205}{69n}x\right)^{\frac{69n}{205x}}\right]^{-\frac{205x}{69}} \to e^{-\frac{205x}{69}} \text{ as } n \to \infty. ] Thus, the integrand converges to ( e^{-\frac{205x}{69}} \cdot e^{-\frac{6}{7}x} = e^{-\left(\frac{205}{69} + \frac{6}{7}\right)x} ).

Now, I need to compute the integral of ( e^{-\left(\frac{205}{69} + \frac{6}{7}\right)x} ) from 0 to (\infty). The integral of ( e^{-k x} ) from 0 to (\infty) is ( \frac{1}{k} ), provided ( k > 0 ).

First, I will compute the coefficient ( k = \frac{205}{69} + \frac{6}{7} ). Then, the limit of the integral will be ( \frac{1}{k} ). Finally, I will express ( \frac{1}{k} ) in reduced form ( \frac{p}{q} ) and compute ( p^2 q ).

[/THOUGHT] [PYTHON] from fractions import Fraction

Compute the coefficient k

k = Fraction(205, 69) + Fraction(6, 7)

Simplify k

k_simplified = Fraction(k).limit_denominator()

The integral evaluates to 1/k

p_over_q = Fraction(1, k_simplified)

Ensure p and q are coprime

p = p_over_q.numerator q = p_over_q.denominator

Compute p^2 q

result = p**2 * q print(result) [/PYTHON]

Tool Output
[PYTHON OUTPUT] 431351361 [/PYTHON OUTPUT]
Reasoning Process

[THOUGHT] The Python output confirms that ( p^2 q = 431351361 ). This is the final answer. [/THOUGHT]

\boxed{431351361}

Final Model Output
431351361

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