Qiangqiang and Fangfang ran back and forth on a straight road 120 meters apart. Qiangqiang ran 2 meters per second, and Fangfang ran 3 meters per second. If two people start from both ends at the same time, how many times do they meet in 15 minutes?
强强、芳芳两人在相距120米的直路上来回跑步，强强每秒跑2米，芳芳每秒跑3米．如果两人同时从两端点出发，那么15分钟内他们共相遇多少次．
<gadget id="calculator">18 + 1</gadget>
<output>19</output>

<result>19</result>