Cars A and B start from AB at the same time and drive toward each other. After 4 hours, the distance between the two cars is still 40% of the distance. It is known that car A takes 20 hours to complete the journey, and car B travels 45 kilometers per hour. What is the speed of the car in kilometers per hour?
甲乙两车从AB两地同时出发相向而行，4小时后，两车还相距全程的40%．已知甲车行完全程要20小时，乙车每小时行45千米．甲车的速度是每小时多少千米？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(3/5) / 4</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(3/20) - (1/20)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">45 / (1/10) / 20</gadget>
<output>45/2 = around 22.5</output>

<result>45/2 = around 22.5</result>