A coin is tossed 3 times, 2 heads and 1 tails. So, what is the probability of tails in 4 tosses of the coin
投掷3次硬币，有2次正面朝上，有1次反面朝上．那么，投掷4次硬币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>