The difference between two numbers A and B is 30, and (3/10) of A is equal to (1/3) of B, what is the sum of these two numbers?
甲、乙两个数的差是30，其中甲数的(3/10)等于乙数的(1/3)，则这两个数的和为多少．
<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1 - (9/10)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">30 / (1/10)</gadget>
<output>300</output>

<gadget id="calculator">300 * (9/10)</gadget>
<output>270</output>

<gadget id="calculator">300 + 270</gadget>
<output>570</output>

<result>570</result>