A train travels from city A to city B and travels 210 kilometers in the first 3 hours. According to this calculation, it can reach city B in another 4.5 hours. How many kilometers are there in total between the two cities? (Solve with ratio)
一列火车从甲城开往乙城，前3小时行驶210千米，照这样计算，再行4.5小时就可以到达乙城，甲乙两城共多少千米？(用比例解)
<gadget id="calculator">210 / 3</gadget>
<output>70</output>

<gadget id="calculator">70 * 3</gadget>
<output>210</output>

<gadget id="calculator">70 * 4.5</gadget>
<output>315</output>

<gadget id="calculator">210 + 315</gadget>
<output>525</output>

<result>525</result>