Two people, A and B, want to complete the same job, and their efficiency ratio is 8:9, and A completes the task 5 hours later than B, how many hours does it take for B to finish the job?
甲、乙二人要完成同样一份工作，其效率比为8：9，甲比乙晚5小时完成任务，那么乙做完工作需要多少小时．
<gadget id="calculator">9 - 8</gadget>
<output>1</output>

<gadget id="calculator">5 / 1</gadget>
<output>5</output>

<gadget id="calculator">5 * 8</gadget>
<output>40</output>

<result>40</result>