The lower base of a trapezoid is 1.5 times the upper base, the height is 18 centimeters, and the area is 540 square centimeters. What is the upper base of the trapezoid in centimeters?
一个梯形的下底是上底的1.5倍，高是18厘米，面积是540平方厘米，则这个梯形的上底是多少厘米．
<gadget id="calculator">2 / 18</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">540 * (1/9)</gadget>
<output>60</output>

<gadget id="calculator">1 + 1.5</gadget>
<output>2.5</output>

<gadget id="calculator">60 / 2.5</gadget>
<output>24</output>

<result>24</result>