There are 3 yellow balls and 2 red balls in an opaque bag, and one ball is randomly touched, the probability of touching a red ball is ((())/(())), how many red balls are added The probability of touching a yellow ball is (3/10).
在一只不透明的袋子里装有3只黄球、2只红球，任意摸1只球，摸到红球的可能性是((())/(()))，再增加多少只红球，摸到黄球的可能性是(3/10)．
<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">3 / (3/10)</gadget>
<output>10</output>

<gadget id="calculator">3 + 2</gadget>
<output>5</output>

<gadget id="calculator">10 - 5</gadget>
<output>5</output>

<result>5</result>