It takes 8 hours for A to go from A to B, and B travels (1/9) of the distance between A and B every hour. A and B start from A. If they want to reach B at the same time, B should go before A. how many hours
甲从A地到B地用8小时，乙每小时行A、B两地路程的(1/9)，甲、乙两人从A地出发，要想同时到达B地乙应比甲先走多少小时
<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">1 / (1/9)</gadget>
<output>9</output>

<gadget id="calculator">9 - 8</gadget>
<output>1</output>

<result>1</result>