A batch of chemical fertilizers was transported 18 tons for the first time, and 1/4 of the total amount was transported for the second time. The weight ratio of the remaining fertilizers to the transported fertilizers is 9:11. How many tons are there in this batch of fertilizers?
一批化肥第一次运走了18吨，第二次运走了总数的(1/4)，剩下的化肥与运走的化肥重量比是9：11，这批化肥共有多少吨？
<gadget id="calculator">9 + 11</gadget>
<output>20</output>

<gadget id="calculator">11 / 20</gadget>
<output>11/20 = around 0.55</output>

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

<gadget id="calculator">(11/20) - (1/4)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">18 / (3/10)</gadget>
<output>60</output>

<result>60</result>