A and B start from A and B at the same time and walk toward each other. After meeting, A travels another 3 hours to reach B, and B travels another 21.6 kilometers to reach A. Given that A's speed is 6 km/h, what is B's speed?
甲、乙两人同时从A、B两地出发，相向而行，相遇后，甲再行3小时到达B地，乙又行21.6千米到达A地．已知甲的速度是6千米/时，则乙的速度是多少？
<gadget id="calculator">6 * 3</gadget>
<output>18</output>

<gadget id="calculator">21.6 / 18</gadget>
<output>1.2</output>

<gadget id="calculator">1 / 1.2</gadget>
<output>0.833333</output>

<gadget id="calculator">6 * 0.833333</gadget>
<output>4.999998</output>

<result>4.999998</result>