On a map with a scale of 1:4,000,000, the distance between Wenzhou and Hangzhou is 9 cm. How long does it take for a car to travel from Wenzhou to Hangzhou at a speed of 90 kilometers per hour?
在一幅比例尺是1：4000000的地图上，量得温州与杭州两地间的距离是9厘米，一辆汽车以每小时90千米的速度从温州到杭州，需行驶几小时？
<gadget id="calculator">1 / 4_000_000</gadget>
<output>1/4_000_000 = around 0</output>

<gadget id="calculator">9 / (1/4_000_000) / 100_000 / 90</gadget>
<output>4</output>

<result>4</result>