A, B from A, and C from B are walking toward each other at the same time. When B and C meet, C travels exactly 60 kilometers. If B turns around and meets A after 30 minutes, B walks to B. Immediately after turning back, it takes 50 minutes to meet A. When A and C meet, C travels exactly 100 kilometers. How many minutes does it take for A to complete the journey?
甲、乙从A地，丙从B地三人同时相向而行，当乙、丙相遇时，丙正好行60千米，若这时乙回头走经过30分钟与甲相遇，乙走到B地后立即回头，还要50分钟与甲相遇，甲、丙相遇时丙正好行100千米，求甲行完全程要多少分钟？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">30 * (1/5) * 3</gadget>
<output>18</output>

<gadget id="calculator">50 * (1/5) * 3</gadget>
<output>30</output>

<gadget id="calculator">18 + 30</gadget>
<output>48</output>

<gadget id="calculator">48 / 3</gadget>
<output>16</output>

<gadget id="calculator">16 * 5</gadget>
<output>80</output>

<gadget id="calculator">50 * 1</gadget>
<output>50</output>

<gadget id="calculator">30 - 30 - 18</gadget>
<output>-18</output>

<gadget id="calculator">50 + (-18)</gadget>
<output>32</output>

<gadget id="calculator">32 / 2</gadget>
<output>16</output>

<gadget id="calculator">48 + 80 + 16</gadget>
<output>144</output>

<gadget id="calculator">144 / 3</gadget>
<output>48</output>

<gadget id="calculator">48 * 5</gadget>
<output>240</output>

<result>240</result>