car drives from place A to place B at 8:00 in the morning, and travels exactly 40% of the journey at 2:00 in the afternoon. At this time, the car is still 105km away from half of the journey. How many kilometers per hour does the car drive on average?
一辆汽车上午8：00从甲地开往乙地，下午2：00正好行了全程的40%，这时汽车离全程的一半还差105km，这辆汽车平均每小时行驶多少千米？
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

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

<gadget id="calculator">105 / (1/10)</gadget>
<output>1_050</output>

<gadget id="calculator">1_050 * (2/5)</gadget>
<output>420</output>

<gadget id="calculator">420 / 6</gadget>
<output>70</output>

<result>70</result>