There are 3 red balls and 8 yellow balls in a pocket, draw a ball randomly from it, what is the probability of drawing a red ball?
在一个口袋里有3个红球和8个黄球，从中任意摸出一个球，摸出红球的可能性是多少．
<gadget id="calculator">3 + 8</gadget>
<output>11</output>

<gadget id="calculator">3 / 11</gadget>
<output>3/11 = around 0.272727</output>

<result>3/11 = around 0.272727</result>