Uncle Wang went from City A to City B. On the first day, he traveled 40% of the whole journey, and on the second day (9/20), he was still 90 kilometers away from City B. How many miles is the distance between A and B?
王叔叔从甲城到乙城，第一天行了全程的40%，第二天行了全程的(9/20)，距乙城还有90千米．甲、乙两城相距多少千米？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">9 / 20</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">1 - (2/5) - (9/20)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">90 / (3/20)</gadget>
<output>600</output>

<result>600</result>