Car A and Car B set off opposite each other at the same time. Car A travels 60 kilometers per hour, and Car B travels 75 kilometers per hour. After 3 hours, the two cars meet. How many kilometers are the distance between the two places?
甲、乙两车同时从两地相对出发，甲车每小时行60千米，乙车每小时行75千米，经过3小时后两车相遇．两地相距多少千米？
<gadget id="calculator">60 + 75</gadget>
<output>135</output>

<gadget id="calculator">135 * 3</gadget>
<output>405</output>

<result>405</result>