and B start from A and B at the same time and walk towards each other for 6 hours before meeting each other. It takes 10 hours for A to walk from point A to point B. A and B are walking towards each other from points A and B respectively. A starts at 6:00 a.m. and arrives at point C on the way, and B starts from point B. When B arrives at C, it is 6:30 p.m. on the same day. Question: How many hours did B travel from point B to point C?
甲、乙两人从A、B两地同时出发，相向而行6小时可以相遇．甲从A地走到B地要10小时，现甲、乙二人分别从A、B两地相向而行，甲在上午6时现出发，到达途中C地时，乙才从B地出发，当乙到达C地时是当日下午6时30分．问：乙从B地到C地共走了几小时？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">12.5 * (1/10)</gadget>
<output>1.25</output>

<gadget id="calculator">1.25 - 1</gadget>
<output>0.25</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/10) - (1/6)</gadget>
<output>-1/15 = around -0.066667</output>

<gadget id="calculator">(1/10) + (-1/15)</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">0.25 / (1/30)</gadget>
<output>7.5</output>

<result>7.5</result>