There are 8 basketballs. The ratio of volleyballs to basketballs is 5:2. How many volleyballs are there?
篮球有8个，排球与篮球的个数比是5：2，排球有多少个．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">8 / (2/5)</gadget>
<output>20</output>

<result>20</result>