The ratio of the bottom areas of two cylindrical containers, A and B, is 4:3. The depth of water in container A is 7 cm, and the depth of water in container B is 3 cm. Then pour the same amount of water into the two containers until the water depths are equal. The water surface of container A should rise how many centimeters?
甲乙两个圆柱形容器底面积之比为4：3，甲容器中水深7厘米，乙容器中水深3厘米，再往两个容器中注入同样多的水直到水深相等，甲容器的水面应上升多少厘米？
<gadget id="calculator">7 - 3</gadget>
<output>4</output>

<gadget id="calculator">4 - 3</gadget>
<output>1</output>

<gadget id="calculator">4 / 1</gadget>
<output>4</output>

<gadget id="calculator">4 * 3</gadget>
<output>12</output>

<result>12</result>