A rides a bicycle and B walks, respectively, from A and B at the same time, and after meeting, A arrives at B after another 15 minutes. If A's speed is three times that of B's, how many minutes will it take for B to reach point A after passing the meeting point?
甲骑车，乙步行，分别从A、B两地同时相向而行，相遇后，甲又经15分钟到达B地．若甲的速度是乙的速度的3倍，乙过相遇地点后经多少分钟到达A地？
<gadget id="calculator">15 * 3</gadget>
<output>45</output>

<gadget id="calculator">45 * 3</gadget>
<output>135</output>

<result>135</result>