There are two piles of rice in the grain store, with a total weight of 19.6 tons. (3/4) of pile A is equal to the weight of pile B. How many tons does pile B weigh?
粮店有两堆大米，共重19.6吨，甲堆的(3/4)与乙堆重量相等，乙堆重多少吨？
<gadget id="calculator">3 + 4</gadget>
<output>7</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">19.6 * (3/7)</gadget>
<output>8.4</output>

<result>8.4</result>