🎲 概率计算器Probability Calculator
输入两个独立事件 A、B 的概率，计算交集、并集、互斥或、都不发生和补集概率；也可计算 n 次重复中至少发生一次的概率。For two independent events A and B: P(A∩B), P(A∪B), exactly one, neither and complements; plus the chance of at least one success in n repeated trials.
使用说明与常见问题How-to & FAQ
「概率计算器」是什么？What is the Probability Calculator tool?
输入两个独立事件 A、B 的概率，计算交集、并集、互斥或、都不发生和补集概率；也可计算 n 次重复中至少发生一次的概率。For two independent events A and B: P(A∩B), P(A∪B), exactly one, neither and complements; plus the chance of at least one success in n repeated trials.
如何使用「概率计算器」？How do I use the Probability Calculator tool?
在「概率计算器」中，填写「P(A)」、「P(B)」、「概率格式」、「重复次数 n(可选)」等参数，结果会随输入实时计算并显示在下方。In the Probability Calculator: Fill in "P(A)", "P(B)", "Probability format", "Repetitions n (optional)"; results are recalculated instantly as you type.
事件不独立怎么办？What if the events are not independent?
本工具假设 A 与 B 相互独立（P(A∩B) = P(A)·P(B)）。不独立时需要已知 P(A∩B) 或条件概率，结果会不同。This tool assumes A and B are independent (P(A∩B) = P(A)·P(B)). For dependent events you need P(A∩B) or a conditional probability, and results differ.
计算精度如何？How precise are the results?
「概率计算器」使用 JavaScript 双精度浮点数（约 15–16 位有效数字）；极大或极小的数值可能存在精度误差。The Probability Calculator uses double-precision floating point (about 15–16 significant digits); very large or very small values may lose precision.
「概率计算器」免费吗？需要注册吗？Is the Probability Calculator free? Do I need an account?
「概率计算器」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Probability Calculator is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.