Xiao Ming walks 75 meters per minute from home to school, and arrives at school in 20 minutes. If you want to arrive at school 5 minutes earlier, how many meters do you have to walk on average per minute?
小明从家到学校，每分钟走75米，20分钟到达学校．如果想提前5分钟到校，平均每分钟要走多少米？
<gadget id="calculator">20 - 5</gadget>
<output>15</output>

<gadget id="calculator">20 / 15</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">75 * (4/3)</gadget>
<output>100</output>

<result>100</result>