Uncle Wang renovates a piece of land at a rate of 60 square decimeters per minute, which can be completed in half an hour. If 80 square decimeters are refurbished per minute, how long will it take to complete the refurbishment? (Solve with ratio)
王大爷整修一块地，每分钟整修60平方分米，半小时可以整修完．如果每分钟整修80平方分米，多长时间可以整修完？(用比例解)
<gadget id="calculator">60 * 30</gadget>
<output>1_800</output>

<gadget id="calculator">1_800 / 80</gadget>
<output>45/2 = around 22.5</output>

<result>45/2 = around 22.5</result>