A pile of coal is transported 8 tons per day, and after several days of transportation, there are still 5 tons left. If the pile of coal is 77 tons in total, how many days has it been transported?
一堆煤，每天运8吨，运了几天后还剩下5吨，如果这堆煤共77吨，问运了多少天？
<gadget id="calculator">77 - 5</gadget>
<output>72</output>

<gadget id="calculator">72 / 8</gadget>
<output>9</output>

<result>9</result>