Xiaoqiang travels from point A to point B at a speed of 3 kilometers per hour. After walking half the distance, in order to arrive earlier, the speed is increased to 5 kilometers per hour. What is the average speed of Xiaoqiang from point A to point B in kilometers per hour? hour.
小强以3千米/时的速度从A地到B地，走了一半路程后，为了提前到达，速度提高到5千米/时，小强从A地到B地的平均速度是多少千米/时．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) / 3</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/2) / 5</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/6) + (1/10)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">1 / (4/15)</gadget>
<output>15/4 = around 3.75</output>

<result>15/4 = around 3.75</result>