The school bought 20 basketballs, and the number of footballs bought was basketballs (3/5). There are more footballs than volleyballs (1/3), how many volleyballs did the school buy?
学校买来20个篮球，买来足球的个数是篮球的(3/5)．足球的数量又比排球多(1/3)，学校买来排球多少个？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

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

<gadget id="calculator">1 + (1/3)</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">(3/5) / (4/3)</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">20 * (9/20)</gadget>
<output>9</output>

<result>9</result>