The ratio of soccer balls to volleyballs in a sporting goods store is 5:12. After selling 2 soccer balls, the ratio of soccer balls to volleyballs is 1:3. How many soccer balls are there?
体育用品店中足球和排球个数的比是5：12，卖了2个足球后，足球与排球的比是1：3，原来有足球多少个．
<gadget id="calculator">5 / 12</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(5/12) - (1/3)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">2 / (1/12)</gadget>
<output>24</output>

<gadget id="calculator">24 * (5/12)</gadget>
<output>10</output>

<result>10</result>