The sailfish is the champion of swimming in the ocean. It can swim 270 kilometers in 3 hours. The dolphin is also an expert swimmer. It can swim 120 kilometers in 2 hours. How much faster is the average speed of a sailfish than a dolphin?
旗鱼是海洋中的游泳冠军，它3小时能游270千米，海豚也是游泳能手，它2小时能游120千米，旗鱼的平均速度比海豚快多少？
<gadget id="calculator">270 / 3</gadget>
<output>90</output>

<gadget id="calculator">120 / 2</gadget>
<output>60</output>

<gadget id="calculator">90 - 60</gadget>
<output>30</output>

<result>30</result>