Dongdong and Xiaoming walk towards each other along a road from two places at the same time. Dongdong's speed is 65 m/min, and Xiao Ming's speed is 75 m/min. After 3 minutes, the distance between the two is 120 meters. How long is the road?
冬冬和小明同时从两地沿一条公路相向走来，冬冬的速度是65米/分，小明的速度是75米/分，经过3分钟两人相距120米，这条公路长多少米？
<gadget id="calculator">65 + 75</gadget>
<output>140</output>

<gadget id="calculator">140 * 3</gadget>
<output>420</output>

<gadget id="calculator">420 + 120</gadget>
<output>540</output>

<result>540</result>