The mass ratio of A and B piles of coal is 3:5, the mass of B pile of coal is 200 tons, and the mass of A pile of coal is how many tons.
甲、乙两堆煤的质量比是3：5，乙堆煤的质量是200吨，甲堆煤的质量是多少吨．
<gadget id="calculator">200 / 5</gadget>
<output>40</output>

<gadget id="calculator">40 * 3</gadget>
<output>120</output>

<result>120</result>