Wang Yan tossed a coin 3 times in a row, 2 heads and 1 tails, what is the probability of tails if the coin is tossed again?
王燕连续掷了3次硬币，2次正面朝上，1次反面朝上，如果再掷一次，反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>