A rectangle has a perimeter of 30 decimeters and its length is 1.5 times its width. How many decimeters is the width of the rectangle?
一个长方形的周长是30分米，它的长是宽的1.5倍．长方形的宽是多少分米？
<gadget id="calculator">1.5 * 2</gadget>
<output>3</output>

<gadget id="calculator">3 + 2</gadget>
<output>5</output>

<gadget id="calculator">30 / 5</gadget>
<output>6</output>

<result>6</result>