The distance between the two places is 15 kilometers. A and B start from the two places at the same time and walk toward each other. After (4/3) hours, they meet on the way. It is known that A travels 6 kilometers per hour, how many kilometers per hour does B travel?
两地相距15千米，甲乙二人从两地同时出发相向而行，经过(4/3)小时在途中相遇，已知甲每小时行6千米，乙每小时行多少千米？
<gadget id="calculator">4 / 3</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">15 / (4/3)</gadget>
<output>45/4 = around 11.25</output>

<gadget id="calculator">(45/4) - 6</gadget>
<output>21/4 = around 5.25</output>

<result>21/4 = around 5.25</result>