Chen Jun drives 85km per hour from place A to place B, and arrives at place B in 3 hours. When returning, travel 90km per hour, how long will it take to return to place A? (Solve with ratio)
陈军开车从甲地到乙地每小时行85km，3小时到达乙地．返回时每小时行90km，多少时间能返回到甲地？(用比例解)
<gadget id="calculator">85 * 3</gadget>
<output>255</output>

<gadget id="calculator">255 / 90</gadget>
<output>17/6 = around 2.833333</output>

<result>17/6 = around 2.833333</result>