certain bank shipped in a batch of rice, 11% of the total in the first shipment, 3 tons in the second shipment, and 31% of the total rice in the two batches. How many tons are there in total in this batch of rice?
某银行运进一批大米，第一次运进总数的11%，第二次运进了3吨，两次共运进这批大米的31%，这批大米一共有多少吨？
<gadget id="calculator">31 / 100</gadget>
<output>31/100 = around 0.31</output>

<gadget id="calculator">11 / 100</gadget>
<output>11/100 = around 0.11</output>

<gadget id="calculator">(31/100) - (11/100)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">3 / (1/5)</gadget>
<output>15</output>

<result>15</result>