and B carry a total of 90 kilograms of luggage on the train, A should pay a baggage fee of 5.6 yuan for the overweight part of the luggage, and B should pay a luggage fee of 4.4 yuan for the overweight part of the luggage. If the luggage of two people is carried by one person, a luggage fee of 14 yuan should be paid for the overweight part. How many kilograms is the weight of free luggage per person on this train?
甲、乙两人共携带90千克行李乘火车，甲携带行李的超重部分应交5.6元的行李费，乙携带行李的超重部分应交4.4元的行李费．如果两人的行李归一人携带，超重部分应交14元的行李费．乘这列火车每人免费携带的行李的重量是多少千克？
<gadget id="calculator">5.6 + 4.4</gadget>
<output>10</output>

<gadget id="calculator">90 / 10</gadget>
<output>9</output>

<gadget id="calculator">90 / 14</gadget>
<output>45/7 = around 6.428571</output>

<gadget id="calculator">9 - (45/7)</gadget>
<output>18/7 = around 2.571429</output>

<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 14</gadget>
<output>1/14 = around 0.071429</output>

<gadget id="calculator">(1/5) - (1/14)</gadget>
<output>9/70 = around 0.128571</output>

<gadget id="calculator">(18/7) / (9/70)</gadget>
<output>20</output>

<result>20</result>