The distance between A and B is 278km. A car travels from A to B at 76km per hour; half an hour later, B travels from B to A at 84km per hour. How many hours does car B meet car A after driving out?
A、B两地相距278km，甲车从A地开往B地，每小时行76km；半小时后，乙车从B地开往A地，每小时行84km．乙车开出几小时后和甲车相遇？
<gadget id="calculator">76 * 0.5</gadget>
<output>38</output>

<gadget id="calculator">278 - 38</gadget>
<output>240</output>

<gadget id="calculator">76 + 84</gadget>
<output>160</output>

<gadget id="calculator">240 / 160</gadget>
<output>3/2 = around 1.5</output>

<result>3/2 = around 1.5</result>