We stipulate that two people take turns to do a project, which means that the first person will do one hour first, the second person will do it for an hour, then the first person will do it for an hour, and then the second person will do it for an hour, and so on. , so far. If it takes 9.8 hours for A and B to do a project in turn, but it only takes 9.6 hours for B and A to do the same project in turn, how many hours does B need to do this project alone?
我们规定两人轮流做一个工程是指，第一个人先做一个小时，第二个人做一个小时，然后再由第一个人做一个小时，然后又由第二个人做一个小时，如此反复，做完为止．如果甲、乙轮流做一个工程需要9.8小时，而乙、甲轮流做同样的工程只需要9.6小时，那乙单独做这个工程需要多少小时？
<gadget id="calculator">2.5 + 4.8</gadget>
<output>7.3</output>

<result>7.3</result>