The distance from Jinan to a place in Beijing is 450 kilometers. Car A and car B set off from Jinan and Beijing on the same route at the same time. They meet after 3 hours. It is known that the speed of car A is 70 km/h. Then the speed of car B is What is the speed?
济南到北京某地距离450千米，汽车A和汽车B分别从济南、北京两地按同一路线同时出发，3小时后相遇，已知汽车A的速度是70千米/时，那么汽车B的时速是多少呢？
<gadget id="calculator">450 / 3</gadget>
<output>150</output>

<gadget id="calculator">150 - 70</gadget>
<output>80</output>

<result>80</result>