Jinqiang Cement Factory produced a batch of cement. 35% of the total mass is shipped out for the first time, 25% of the total mass is shipped out for the second time, and a total of 900 tons are shipped out twice. How many tons is this batch of cement?
金强水泥厂生产了一批水泥．第一次运出总质量的35%，第二次运出总质量的25%，两次共运出900吨．这批水泥共有多少吨？
<gadget id="calculator">35 / 100</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(7/20) + (1/4)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">900 / (3/5)</gadget>
<output>1_500</output>

<result>1_500</result>