A rectangular swimming pool is 25 meters wide and twice as long as it is wide. Find the perimeter of the swimming pool.
一个长方形游泳池，宽是25米，长是宽的2倍，求这个游泳池的周长．
<gadget id="calculator">25 * 2</gadget>
<output>50</output>

<gadget id="calculator">50 + 25</gadget>
<output>75</output>

<gadget id="calculator">75 * 2</gadget>
<output>150</output>

<result>150</result>