car travels 45 kilometers per hour and can reach the destination in 20 hours. In fact, there are more lines (1/3) per hour. How many hours can it reach? (Solution with proportional knowledge)
一辆汽车每小时行驶45千米，20小时可以到达目的地，实际每小时多行(1/3)，可以多少小时到达？(用比例知识解)
<gadget id="calculator">45 * 20</gadget>
<output>900</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">45 * (1/3)</gadget>
<output>15</output>

<gadget id="calculator">45 + 15</gadget>
<output>60</output>

<gadget id="calculator">900 / 60</gadget>
<output>15</output>

<result>15</result>