The distance between the two cities is 525km, Xiaoli drives 56km per hour, and Xiaoqiang drives 63km per hour. Three hours after Xiaoli set off from one city, Xiaoqiang drove from another city and drove toward Xiaoli. How many hours later did the two cars meet?
两个城市相距525km，小丽驾车每小时行56km，小强驾车每小时行63km．小丽从一个城市出发3小时后，小强从另一个城市开出，与小丽相向而行，又经过几小时两车相遇？
<gadget id="calculator">56 * 3</gadget>
<output>168</output>

<gadget id="calculator">525 - 168</gadget>
<output>357</output>

<gadget id="calculator">56 + 63</gadget>
<output>119</output>

<gadget id="calculator">357 / 119</gadget>
<output>3</output>

<result>3</result>