There is a batch of chemical fertilizers in the warehouse, 30 tons are taken out for the first time, and (1/4) of the total number is taken out for the second time, leaving 45% of the total amount. How many tons are there in this batch of chemical fertilizers?
仓库有一批化肥，第一次取出30吨，第二次取出总数的(1/4)，还剩总数的45%，这批化肥有多少吨？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">45 / 100</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">1 - (1/4) - (9/20)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">30 / (3/10)</gadget>
<output>100</output>

<result>100</result>