There are 12 table tennis balls of the same size in a box, among which there are 5 yellow ones and 7 white ones, what is the probability of touching a white ball?
盒子里有12个大小相同的乒乓球，其中有5个黄色的，7个白色的，摸到白球的可能性是多少．
<gadget id="calculator">7 / 12</gadget>
<output>7/12 = around 0.583333</output>

<result>7/12 = around 0.583333</result>