It takes 4 hours for a car to travel 45km per hour from place A to place B. When returning, the speed increases (1/9), how many hours does it take?
一辆汽车由甲地开往乙地，每小时行45km，需4小时，回来时，速度提高(1/9)，需要多少小时？
<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">45 * (1/9)</gadget>
<output>5</output>

<gadget id="calculator">45 + 5</gadget>
<output>50</output>

<gadget id="calculator">4 / 50</gadget>
<output>2/25 = around 0.08</output>

<gadget id="calculator">45 * (2/25)</gadget>
<output>18/5 = around 3.6</output>

<result>18/5 = around 3.6</result>