There is an indoor playground in Hongxing Primary School, which is 50 meters long and twice as wide. What is the perimeter of the playground?
红星小学有一个室内活动场，长50米，是宽的2倍，这个活动场的周长是多少？
<gadget id="calculator">50 / 2</gadget>
<output>25</output>

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

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

<result>150</result>