The distance between A and B is 180 kilometers. It is scheduled to take 10 hours to travel from A to B by bicycle. When the bicycle travels halfway, it takes 1 hour to repair the bicycle. If you arrive at B according to the original time, then What is the speed of the bicycle in kilometers per hour during the second half of the journey?
A、B两地相距180千米，骑自行车原定用10小时从A地到B地，当自行车行了一半路程时，因修单车用了1小时，若按原定时间到达B地，那么自行车在后半段路程中的速度是每小时多少千米．
<gadget id="calculator">180 / 2</gadget>
<output>90</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">90 / 4</gadget>
<output>45/2 = around 22.5</output>

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