There are 10 red balls and 5 white balls of the same size in a box, if you touch a ball randomly from the box, what is the probability of getting a red ball (fill in the score)
盒子里装有大小相同的10个红球和5个白球，从盒子里任意摸一个球，摸到红球的可能性多少(填分数)
<gadget id="calculator">10 + 5</gadget>
<output>15</output>

<gadget id="calculator">10 / 15</gadget>
<output>2/3 = around 0.666667</output>

<result>2/3 = around 0.666667</result>