The recycling rate of recycled paper produced from waste paper is 80%. Limin Paper Mill produced 120 tons of recycled paper from recycled waste paper. How many tons of waste paper need to be recycled to produce these recycled paper?
用废纸生产再生纸的再生率为80%，利民造纸厂用回收的废纸生产了120吨再生纸．这些再生纸需要回收多少吨废纸才能生产出来？
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">120 / (4/5)</gadget>
<output>150</output>

<result>150</result>