Two teams of students, A and B, set off from two places 31.5 kilometers apart at the same time and walk toward each other. A student rides a bicycle at a speed of 14 kilometers per hour, and keeps in touch between the two teams. The speed of team A is 5 kilometers per hour, and the speed of team B is 4 kilometers per hour. When the two teams meet, the student riding a bicycle How many kilometers did you travel in total?
甲、乙两队学生从相距31.5千米的两地同时出发，相向而行．一个同学骑自行车以每小时14千米的速度，在两队间不停地往返联络，甲队速度是每小时5千米，乙队每小时4千米，两队相遇时，骑自行车的同学共行了多少千米？
<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">31.5 / 9</gadget>
<output>3.5</output>

<gadget id="calculator">14 * 3.5</gadget>
<output>49</output>

<result>49</result>