coin is tossed 3 times, 2 heads and 1 tails. What is the probability of heads on the 4th toss of the coin?
投掷3次硬币，有2次正面朝上，1次反面朝上．那么，投掷第4次硬币正面朝上的可能性为多少．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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