Two people, A and B, are walking towards each other from two places 45 kilometers apart. A starts from point A and walks toward B at 6 kilometers per hour. After 2 hours, B starts from point B and walks toward point A, and B leaves. When meeting A in 3 hours, what is the speed of B in kilometers?
甲、乙两人从相距45千米的两地相向而行，甲从A地出发向B走，每小时行6千米，2小时后，乙从B地出发向A地走，乙走了3小时遇见甲，乙的速度是多少千米．
<gadget id="calculator">6 * 2</gadget>
<output>12</output>

<gadget id="calculator">45 - 12</gadget>
<output>33</output>

<gadget id="calculator">33 / 3</gadget>
<output>11</output>

<gadget id="calculator">11 - 6</gadget>
<output>5</output>

<result>5</result>