A person walks (9/2) kilometers per hour from A to B, and rides a bicycle to travel (45/4) kilometers per hour when returning. Cycling takes (2/5) less hours than walking. So how many hours did he ride the bike?
某人从甲地到乙地步行每小时走(9/2)千米，回来时骑自行车每小时行(45/4)千米，骑自行车比走路少(2/5)小时．那么他骑车用了多少小时？
<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(5/2) * (2/3)</gadget>
<output>5/3 = around 1.666667</output>

<result>5/3 = around 1.666667</result>