某电子设备需通过“字母大小写信号”验证字符串“@Neuroplexus”，其中“@”为固定通路，其余...

Created on: October 3, 2025

Answered using GPT-5 Thinking by Chat01

Question

某电子设备需通过“字母大小写信号”验证字符串“@Neuroplexus”，其中“@”为固定通路，其余11个字母对应11个独立的“开关”——开关闭合（大写）时传递1个电信号，开关断开（小写）时传递0个电信号。

若每个开关闭合概率均为0.5，求“恰好有3个字母为大写（即3个开关闭合）”的概率；
若设备仅识别“首字母N（对应开关1）和尾字母S（对应开关11）同时闭合”的信号，求设备能识别的信号组合总数。

Python

python
import fractions
from math import comb
comb(11,3), comb(11,3)/2**11


(165, 0.08056640625)

Thought

Evaluating recognized signal combinations

The device only recognizes signals where the first and last switches are closed (uppercase), while the other 9 switches can be either open or closed. So, the total number of valid signal combinations is 2^9 = 512. It looks like we just need the count of these combinations, not the probability, so that’s straightforward!

Final answer for signal combinations

The device recognizes signals where the first letter "N" and the last letter "S" are simultaneously closed, meaning both must be uppercase. The other 9 switches can be any combination. Therefore, the total number of signal combinations is 2^9 = 512. Here's the concise solution:

公式： 2^9 = 512.

Thought for 23s

Answer

题目里共有 11 个独立开关（对应“Neuroplexus”的 11 个字母）。

恰好有 3 个大写的概率
$X\sim\mathrm{Binomial}(n=11,p=0.5)$

\Pr(X=3)=\binom{11}{3}(0.5)^{11} =\frac{165}{2048}\approx 0.08056640625\ (\approx 8.06\%)

仅当首字母 N（开关1）和尾字母 S（开关11）同时闭合时可识别
固定这两个为“闭合”，其余 9 个开关任意，因此可识别的组合数为

2^9=512.

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