There are 5 red balls, 2 white balls and 3 yellow balls in the bag, what is the probability of touching the white balls?
袋子里有5个红球，2个白球，3个黄球，则摸到白球的可能性是多少．
<gadget id="calculator">5 + 2 + 3</gadget>
<output>10</output>

<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>