There are pencils of the same specification in a box, 3 of which are red. 2 are blue and 5 are black. If you take out one at random, what is the probability of getting black?
一个盒子里放有规格相同的铅笔，其中3支是红色的．2支是蓝色的，5支是黑色的．如果随意拿出一支用，那么拿到黑色可能性是多少
<gadget id="calculator">5 + 3 + 2</gadget>
<output>10</output>

<gadget id="calculator">5 / 10</gadget>
<output>1/2 = around 0.5</output>

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