Use a scale of 1:6000000 to draw a map. The distance between Nanjing and Beijing on the map is 15 cm. If the scale of 1:9000000 is used instead, how many centimeters should be drawn on the map.
用1：6000000的比例尺画图，南京到北京的图上距离是15厘米，如改用1：9000000的比例尺，在地图上应画多少厘米．
<gadget id="calculator">1 / 6_000_000</gadget>
<output>1/6_000_000 = around 0</output>

<gadget id="calculator">15 / (1/6_000_000)</gadget>
<output>90_000_000</output>

<gadget id="calculator">1 / 9_000_000</gadget>
<output>1/9_000_000 = around 0</output>

<gadget id="calculator">90_000_000 * (1/9_000_000)</gadget>
<output>10</output>

<result>10</result>