Two vehicles A and B transport a batch of cement together. When the transportation is over, vehicle A has transported 18 tons more than the total (7/15), and the ratio of the tons transported by vehicle B to that of vehicle A is 1:2. How many tons?
甲乙两车共运一批水泥，运完时，甲车运了总数的(7/15)多运18吨，乙车运的吨数与甲车的比是1：2，这批水泥一共有多少吨？
<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">7 / 15</gadget>
<output>7/15 = around 0.466667</output>

<gadget id="calculator">(2/3) - (7/15)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">18 / (1/5)</gadget>
<output>90</output>

<result>90</result>