Teacher Liu wanted to call Xiaodong's family, but forgot one of the numbers for a while, and only remembered that it was 86542*. She dialed one by one, and what is the possibility of exactly one call.
刘老师要给小东家打电话，可是一时忘记了其中一个数，只记得是86542*，她逐一拨打，恰好一次拨通的可能性是多少．
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<result>1/10 = around 0.1</result>