Ning Ning and Ping Ping walk the same distance, Ning Ning completes the walk in 6 minutes, Ping Ping completes the walk in 10 minutes, if the two walk towards each other, how long will it take for the two to meet?
宁宁和平平走同一段路，宁宁6分钟走完，平平10分钟走完，如果两人相对而行，多长时间两人能相遇？
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/6) + (1/10)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">1 / (4/15)</gadget>
<output>15/4 = around 3.75</output>

<result>15/4 = around 3.75</result>