The two brothers and sisters set off from home to school at the same time. The elder brother walked 80 meters per minute, and the younger sister walked 50 meters per minute. To my sister. How far is his home from school?
兄妹俩人同时从家出发去学校，哥哥每分钟走80米，妹妹每分钟走50米，哥哥到校门口时，发现忘带语文课本，立即返回家去拿，他在离学校150米处遇到妹妹．他家离学校有多远？
<gadget id="calculator">80 - 50</gadget>
<output>30</output>

<gadget id="calculator">2 / 30</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">150 * (1/15) * 50</gadget>
<output>500</output>

<gadget id="calculator">500 + 150</gadget>
<output>650</output>

<result>650</result>