A car drives from City A to City B, and travels 60% of the journey in 3 hours, which is exactly 45 kilometers away from the midpoint. How many miles is the distance between city A and city B?
一辆汽车从甲城开往乙城，3小时行了全程的60%，刚好离中点45千米．甲城和乙城相距多少千米？
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(3/5) - (1/2)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">45 / (1/10)</gadget>
<output>450</output>

<result>450</result>