A and B start from point A to two opposite places. A rides a bicycle and B walks. A is faster than B by 5 kilometers per hour. After 3 hours, the distance between the two is 27 kilometers. How many kilometers does B travel per hour?
甲乙二人从A点向相反的两地出发，甲骑车，乙步行，甲每小时比乙每小时快5千米，3小时后两人相距27千米．乙每小时行多少千米？
<gadget id="calculator">27 / 3</gadget>
<output>9</output>

<gadget id="calculator">9 + 5</gadget>
<output>14</output>

<gadget id="calculator">14 / 2</gadget>
<output>7</output>

<gadget id="calculator">9 - 7</gadget>
<output>2</output>

<result>2</result>