Xiao Ming tosses a coin, there are 3 heads and 1 tails, and the 5th toss, what is the probability of heads?
小明抛硬币，有3次正面朝上，一次反面朝上，第5次抛掷，正面朝上的可能性是多少．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>