Two cars drive toward each other from two places 456 kilometers apart, and meet after 3 hours. It is known that the speed of car A is 72 km/h, what is the speed of car B?
两辆轿车从相距456千米的两地相向而行，经3小时相遇．已知甲车的速度是72千米/小时，乙车的速度是多少？
<gadget id="calculator">456 / 3</gadget>
<output>152</output>

<gadget id="calculator">152 - 72</gadget>
<output>80</output>

<result>80</result>