It is known that the speed of the slow train is (1/2) that of the express train, and the two trains travel towards each other from stations A and B at the same time and meet at a place 4 kilometers away from the midpoint. What is the distance in kilometers between A and B?
已知慢车的速度是快车的(1/2)，两车从甲乙两站同时相向而行在离中点4千米的地方相遇．求甲乙两站的距离是多少千米？
<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">8 / (1/2)</gadget>
<output>16</output>

<gadget id="calculator">16 * (1/2)</gadget>
<output>8</output>

<gadget id="calculator">8 + 16</gadget>
<output>24</output>

<result>24</result>