There are only 3 red balls and 7 yellow balls of the same size in the pocket, one ball is randomly drawn out each time (put it back after being drawn out), what is the probability of touching the red ball
口袋里只有大小相同的3个红球和7个黄球，每次任意摸出1个球(摸出后再放回)，摸到红球的可能性是多少
<gadget id="calculator">3 + 7</gadget>
<output>10</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<result>3/10 = around 0.3</result>