The length of one circle of the playground runway is (2/5) km. It took (2/15) hours for Xiaohua to run 4 laps, how many kilometers per hour on average?
操场跑道一圈长(2/5)千米．小华跑4圈用了(2/15)小时，平均每小时跑多少千米？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">2 / 15</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">(2/15) / 4</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(2/5) / (1/30)</gadget>
<output>12</output>

<result>12</result>