A train travels from station A to station B, and it arrives in 5 hours. It has been running for 2 hours, and it is 64 kilometers away from the end point. How many kilometers is the distance between A and B stations?
一列火车从A站开往B站，5小时到达，现已行驶了2小时，距离终点还有64千米，AB两站相距多少千米？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/2) - (2/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">64 / (1/10)</gadget>
<output>640</output>

<result>640</result>