If a pile of coal is transported by 7 trucks with a load of 2.5 tons, it will be transported just 4 times. Now switch to a truck with a load of 5 tons to transport it all at once, how many trucks are needed.
一堆煤如果用7辆载重2.5吨的卡车运，4次刚好运完．现在改用载重5吨的卡车一次运完，需要多少辆卡车．
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">7 * 2.5 * (4/5)</gadget>
<output>14</output>

<result>14</result>