Two trains, A and B, depart from two places 700 meters apart. Train A travels 80 kilometers per hour, and train B travels 75 kilometers per hour. One hour after train A departs, train B will depart again. After how many hours did the car meet with car A?
甲、乙两列火车从相距700米的两地相对开出，甲车每小时行80千米，乙车每小时行75千米，甲车开出1小时后，乙车再开出，乙车开出多少小时后与甲车相遇？
<gadget id="calculator">80 * 1</gadget>
<output>80</output>

<gadget id="calculator">700 - 80</gadget>
<output>620</output>

<gadget id="calculator">80 + 75</gadget>
<output>155</output>

<gadget id="calculator">620 / 155</gadget>
<output>4</output>

<result>4</result>