It takes 90 meters to build a road in two days. According to this calculation, the road can be completed in 72 days. How many meters is the total length of the road? (Solve with ratio)
修一条公路，两天修了90米，照这样计算，72天可以修完这条公路，这条公路全长多少米？(用比例解)
<gadget id="calculator">90 * 72</gadget>
<output>6_480</output>

<gadget id="calculator">6_480 / 2</gadget>
<output>3_240</output>

<result>3_240</result>