A car drives from City A to City B. It travels 25% of the distance in the first hour and 90 kilometers in the second hour. At this time, it is still 9/20 of the distance from City B. How many miles is the distance between A and B?
一辆汽车从甲城开往乙城，第一小时行驶了全程的25%，第二小时行驶了90千米，这时距乙城还有全程的(9/20)．甲、乙两城相距多少千米？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

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

<gadget id="calculator">1 - (1/4) - (9/20)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">90 / (3/10)</gadget>
<output>300</output>

<result>300</result>