There are 5 white balls, 10 blue balls, and 10 black balls in a bag. If you reach out and touch it, what is the probability of getting a white ball?
袋子里有5个白球，10个蓝球，10个黑球，伸手一摸，摸到白球的可能性是多少．
<gadget id="calculator">5 + 10 + 10</gadget>
<output>25</output>

<gadget id="calculator">5 / 25</gadget>
<output>1/5 = around 0.2</output>

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