correspondent drives from place A to place B to pick up an important document, and immediately returns to place A by the same route when he arrives at place B, which takes (35/6) hours for the round trip. It is known that the travel time is 63 kilometers per hour, which is (7/8) of the return speed. How many miles is the distance between A and B?
某通讯员开车从A地到B地取一份重要文件，到了B地立刻按原路返回A地，这样往返共用(35/6)小时．已知去时每小时行63千米，是返回时速度的(7/8)．AB两地相距多少千米？
<gadget id="calculator">35 / 6</gadget>
<output>35/6 = around 5.833333</output>

<gadget id="calculator">1 / 63</gadget>
<output>1/63 = around 0.015873</output>

<gadget id="calculator">7 / 8</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">63 / (7/8)</gadget>
<output>72</output>

<gadget id="calculator">1 / 72</gadget>
<output>1/72 = around 0.013889</output>

<gadget id="calculator">(1/63) + (1/72)</gadget>
<output>5/168 = around 0.029762</output>

<gadget id="calculator">(35/6) / (5/168)</gadget>
<output>196</output>

<result>196</result>