Three cars, A, B, and C, drive from point A to point B, which is thousands of miles away. B starts 40 minutes later than A, and catches up with A 160 minutes after departure; C starts 20 minutes later than B, and catches up with B 5 hours after departure. So if A starts 10 minutes before B, and B starts 10 minutes before C, how long will C catch up with A after B catches up with A?
甲乙丙三辆汽车分别从A地开往千里之外的B地．乙比甲晚出发40分钟，出发后160分钟后能追上甲；丙比乙晚出发20分钟，出发后5小时追上乙．那么如果甲比乙先出发10分钟，乙比丙先出发10分钟，那么乙追上甲之后过多久丙能追上甲？
<gadget id="calculator">10 + 10</gadget>
<output>20</output>

<gadget id="calculator">16 - 12</gadget>
<output>4</output>

<gadget id="calculator">12 / 4</gadget>
<output>3</output>

<gadget id="calculator">20 * 3</gadget>
<output>60</output>

<gadget id="calculator">60 + 10 + 10</gadget>
<output>80</output>

<gadget id="calculator">15 - 12</gadget>
<output>3</output>

<gadget id="calculator">12 / 3</gadget>
<output>4</output>

<gadget id="calculator">10 * 4</gadget>
<output>40</output>

<gadget id="calculator">40 + 10</gadget>
<output>50</output>

<gadget id="calculator">80 - 50</gadget>
<output>30</output>

<result>30</result>