Two cars, A and B, start from A and B at the same time. After meeting, A continues to drive to B, and B immediately returns to B. A arrives at B 30 minutes later than B. It is known that A's speed is B's (3/4), how long does it take for A and B to meet each other?
甲乙两车分别从A、B两地同时相向出发，相遇后甲继续向B地开，乙立即返回也向B地开，甲比乙晚到B地30分钟．已知甲的速度是乙的(3/4)，要求甲乙两车从出发到相遇需要多少时间？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 - (3/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">0.5 / (1/4)</gadget>
<output>2</output>

<gadget id="calculator">3 + 4</gadget>
<output>7</output>

<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">2 / (4/7)</gadget>
<output>7/2 = around 3.5</output>

<result>7/2 = around 3.5</result>