Xiaohua goes to school in the morning, takes 15 minutes to get from home to school, and walks an average of 60 meters per minute. When returning home from school in the afternoon, he walks 10 meters less per minute than in the morning. How many minutes does it take Xiaohua to get from school to home?
小华早晨上学，从家到学校用15分钟，平均每分钟走60米，下午放学回家，比早晨每分钟少走10米，小华从学校到家需要多少分钟．
<gadget id="calculator">60 - 10</gadget>
<output>50</output>

<gadget id="calculator">15 / 50</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">60 * (3/10)</gadget>
<output>18</output>

<result>18</result>