The distance between A and B is 630 kilometers. It takes 10 hours for the fast train to travel the entire distance, and 15 hours for the slow train to travel the entire distance. The two trains depart from the two places at the same time. When will they meet?
甲乙两地相距630千米，快车行驶完全程要10小时，慢车行驶完全程要15小时，两车同时从两地相对开出，几小时相遇？
<gadget id="calculator">630 / 10</gadget>
<output>63</output>

<gadget id="calculator">630 / 15</gadget>
<output>42</output>

<gadget id="calculator">63 + 42</gadget>
<output>105</output>

<gadget id="calculator">630 / 105</gadget>
<output>6</output>

<result>6</result>