Xiao Ming’s house is on the east side of the school, and Dong Dong’s house is on the west side of the school. The two distances from the school are exactly the same. The distance between the two families is 900 meters. Xiao Ming can walk 50 meters per minute, and Dongdong can walk 60 meters per minute. Starting from home and meeting at the school gate, who should go first? How many minutes to go first?
小明家在学校东面，东东家在学校的西面，两家离学校的路程正好相等，两家相距900米，小明每分钟能走50米，东东每分钟能走60米，两人如果从家出发，正好在校门口相遇，谁应该先走？先走多少分钟？
<gadget id="calculator">900 / 2</gadget>
<output>450</output>

<gadget id="calculator">450 / 50</gadget>
<output>9</output>

<gadget id="calculator">450 / 60</gadget>
<output>15/2 = around 7.5</output>

<gadget id="calculator">9 - (15/2)</gadget>
<output>3/2 = around 1.5</output>

<result>3/2 = around 1.5</result>