car travels 45 km per hour from A to B. When returning, travel 63km per hour, how much speed increase when returning?
一辆汽车从甲地去乙地每小时行驶45km．返回时每小时行驶63km，返回时速度提高了百分之几？
<gadget id="calculator">63 - 45</gadget>
<output>18</output>

<gadget id="calculator">18 / 45</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>