A and B walk towards each other from two places at the same time, and after 4 hours, they meet at a distance of 4 kilometers from the midpoint. A is faster than B, how many kilometers per hour is A faster than B?
甲乙二人从两地同时相对而行，经过4小时，在距离中点4千米处相遇．甲比乙速度快，甲每小时比乙快多少千米？
<gadget id="calculator">2 / 4</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">4 * (1/2)</gadget>
<output>2</output>

<result>2</result>