The perimeter of a rectangular piece of land is 150 meters, and its length to width ratio is 4:1. What is the length of this piece of land?
一块长方形地周长是150米，它的长和宽比是4：1，这块地的长是多少？
<gadget id="calculator">150 / 2</gadget>
<output>75</output>

<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">75 * (4/5)</gadget>
<output>60</output>

<result>60</result>