Plant sweet potatoes in a rectangular field with a length of 45 meters and a width of 20 meters. Each tree covers an average area of 15 square meters, and each tree harvests 2.5 kilograms of sweet potatoes. How many kilograms of sweet potatoes are harvested in this field?
在一块长45米，宽20米的长方形地里栽白薯，平均每棵占地15平方米，每棵收白薯2.5千克．这块地共收白薯多少千克？
<gadget id="calculator">20 / 15</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">45 * (4/3) * 2.5</gadget>
<output>150</output>

<result>150</result>