certain area transported relief supplies for the disaster area. On the first day (1/4) of the supplies were transported away, and 20% of the supplies were transported on the second day. A total of 180 tons of supplies were transported in these two days. How many tons?
某地区为灾区运送救灾物资，第一天运走这批物资的(1/4)，第二天运走这批物资的20%，这两天共运走物资180吨，这批救灾物资共多少吨？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/4) + (1/5)</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">180 / (9/20)</gadget>
<output>400</output>

<result>400</result>