There is an existing project, which can be completed in 63 days by A alone, and then 28 days by B. If A and B cooperate, it will take 48 days to complete the task. Now A will do it for 42 days first, and then B will complete it. How many more days will it take?
现有一项工程，甲先单独做63天，再由乙做28天即可完成，如果甲乙合作需要48天完成任务．现在甲先做42天，然后乙来完成，还需要几天？
<gadget id="calculator">48 / 1</gadget>
<output>48</output>

<gadget id="calculator">48 + 8</gadget>
<output>56</output>

<result>56</result>