Put 2 red balls and 2 yellow balls in a black cloth bag, touch a ball randomly in it, touch 30 times, what is the approximate number of touches of red balls in the total number of times
在一个黑布袋里放2个红球和2个黄球，明明在里面任意摸一只球，摸30次，摸到红球的次数大约占总次数的多少
<gadget id="calculator">2 + 2</gadget>
<output>4</output>

<gadget id="calculator">2 / 4</gadget>
<output>1/2 = around 0.5</output>

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