A cuboid fuel tank is 40 decimeters wide, its length is 3/2 of its width, and its height is its width of 3/4. If the surface of the cuboid fuel tank is coated with anti-rust paint, 5 grams of anti-rust paint is required per square decimeter, how many grams of anti-rust paint should be used at least once?
一个长方体油箱，宽40分米，长是宽的(3/2)，高是宽的(3/4)．如果给长方体油箱的外表涂防锈漆，每平方分米需用防锈漆5克，刷一遍至少用防锈漆多少克？
<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">40 * (3/2)</gadget>
<output>60</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">40 * (3/4)</gadget>
<output>30</output>

<gadget id="calculator">60 * 30</gadget>
<output>1_800</output>

<gadget id="calculator">60 * 40</gadget>
<output>2_400</output>

<gadget id="calculator">30 * 40</gadget>
<output>1_200</output>

<gadget id="calculator">1_800 + 2_400 + 1_200</gadget>
<output>5_400</output>

<gadget id="calculator">5_400 * 2</gadget>
<output>10_800</output>

<gadget id="calculator">10_800 * 5</gadget>
<output>54_000</output>

<result>54_000</result>