The ratio of the time it takes for A and B to complete the journey by bicycle in AB and AB is 4:5. If A and B ride opposite to each other from AB at the same time, they will meet after 40 minutes, and they will continue to move forward after meeting. In this way, How many minutes later does B arrive at A than A arrives at B?
AB两地，甲乙两人骑自行车行完全程所用时间的比是4：5，如果甲乙二人分别同时从AB两地相对行使，40分钟后两人相遇，相遇后各自继续前行，这样，乙到达A地比甲到达B地要晚多少分钟？
<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">40 / (4/9)</gadget>
<output>90</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">40 / (5/9)</gadget>
<output>72</output>

<gadget id="calculator">90 - 72</gadget>
<output>18</output>

<result>18</result>