There are 15 white balls, 12 red balls and 3 curly balls in a box. Close your eyes and draw one randomly. What is the probability of drawing a red ball?
盒里有15个白球，12个红球和3个花球，闭上眼睛从中任意摸出一个，摸出红球的可能性是多少
<gadget id="calculator">15 + 12 + 3</gadget>
<output>30</output>

<gadget id="calculator">12 / 30</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>