There are 3 red balls and 2 white balls in a box, they have the same shape and size, what is the probability of drawing a white ball from them?
盒子里有3个红球，2个白球，它们的形状、大小相同，从中摸出白球的可能性是多少．
<gadget id="calculator">3 + 2</gadget>
<output>5</output>

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

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