The distance between the two places is 15 kilometers. A and B start from the two places at the same time and walk towards each other. They meet after (3/2) hours. A travels 4 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(3/2)小时相遇．甲每小时行4千米，乙每小时行多少千米？
<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">4 * (3/2)</gadget>
<output>6</output>

<gadget id="calculator">15 - 6</gadget>
<output>9</output>

<gadget id="calculator">9 / (3/2)</gadget>
<output>6</output>

<result>6</result>