25% of a batch of chemical fertilizers were transported away first, and then 18 tons were transported away. At this time, 45% remained unshipped. How many tons of this batch of chemical fertilizers are there?
一批化肥先运走25%，又运走18吨，这时还剩45%没有运，这批化肥共有多少吨？
<gadget id="calculator">25 / 100</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">18 / (3/10)</gadget>
<output>60</output>

<result>60</result>