car travels from A to B. If you reduce the speed by 10%, you will arrive 1 hour later than the original time. If you drive 180 kilometers at the original speed and increase the speed by 20%, you will arrive 1 hour earlier than the original time. What is the distance in miles between A and B?
一辆车从甲地开往乙地．如果把车速减少10%，那么要比原定时间迟1小时到达，如果以原速行驶180千米，再把车速提高20%，那么可比原定时间早1小时到达．甲、乙两地之间的距离是多少千米？
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

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

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">10 * (9/10)</gadget>
<output>9</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">(9/10) / (6/5)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">10 * (3/4)</gadget>
<output>15/2 = around 7.5</output>

<gadget id="calculator">9 - (15/2)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">1 / (3/2)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">180 / (1/3)</gadget>
<output>540</output>

<result>540</result>