Li Ming walks 4 kilometers per hour from school to the Children's Palace, and can arrive there in 1.5 hours. How many hours will it take to travel 3 kilometers per hour?
李明从学校到少年宫，每小时走4千米，1.5小时可以到达．如果每小时只走3千米，要多少小时才能到达？
<gadget id="calculator">1.5 / 3</gadget>
<output>0.5</output>

<gadget id="calculator">4 * 0.5</gadget>
<output>2</output>

<result>2</result>