The distance between the two places is 405 meters. Cars A and B are traveling towards each other from the two places. If car A leaves one hour first, then the two cars will meet after 5 hours of departure; if car B travels 105 kilometers first, then the two cars will meet 4 hours after car B leaves. What is the speed of the car?
两地距离405米，甲乙两车分别从两地相向而行．如果甲车先出发一小时，那么乙出发5小时后两车相遇；如果乙先行105千米，那么乙车出发后4小时两车相遇．甲车的速度是多少？
<gadget id="calculator">405 - 105</gadget>
<output>300</output>

<gadget id="calculator">300 / 4</gadget>
<output>75</output>

<gadget id="calculator">75 * 5</gadget>
<output>375</output>

<gadget id="calculator">405 - 375</gadget>
<output>30</output>

<result>30</result>