同时抛掷3枚相同的硬币，计算正面都朝上的概率，这是常见的一种游戏．本文研究将相同的n枚硬币同时抛出．如何计算n枚硬币同是正面朝上的概率及其推广和应用．概率模型将1枚硬币抛出，正面朝上的概率是(1/2)，即(1/2~1)．用树状图验证如图1．将相同的2枚硬币同时抛出，2枚硬币同是正面朝上的概率是(1/4)，即(1/2~2)．用树状图验证如图2．将相同的3枚硬币同时抛出，3枚 At the same time throwing three identical coins, calculating the probability that the front is facing up, this is a common game. This article studies throwing the same n coins at the same time. How to calculate the probability that n coins are facing up and their generalization and application. The probabilistic model throws a coin with a probability of face up (1/2), ie (1/2~1). Verify with a tree diagram as shown in Figure 1. When the same two coins are thrown at the same time, the probability that two coins are facing up is (1/4), ie (1/2~2). Verify with a tree diagram as shown in Figure 2. Throw the same 3 coins at the same time, 3 pieces