For a batch of goods, 25% of the total amount was transported on the first day, and the ratio of goods transported on the second day to that on the first day was 6:5, leaving 450 tons undelivered. How many tons is this shipment in total?
有一批货物，第一天运走总数的25%，第二天与第一天所运货物的比是6：5，还剩450吨没有运．这批货物共有多少吨？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">6 / 5</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">(1/4) * (6/5)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (1/4) - (3/10)</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">450 / (9/20)</gadget>
<output>1_000</output>

<result>1_000</result>