How many different three-digit numbers can be formed by using three number cards with 0, 5, and 7 written on them respectively; Sex is ((())/(())).
用分别写有0、5、7的三张数字卡片，能摆出多少个不同的三位数；若将三张卡片放入一袋中，每次任意摸两张卡片，摸到5的可能性是((())/(()))．
<gadget id="calculator">2 * 2 * 1</gadget>
<output>4</output>

<result>4</result>