Lingling helps her mother with housework. It takes 15 minutes to boil water, 3 minutes to sweep the floor, 9 minutes to tidy up the room, and 2 minutes to make tea. How many minutes does it take her to finish these tasks?
玲玲帮妈妈做家务，烧开水用15分钟，扫地用3分钟，整理房间用9分钟，沏茶用2分钟，她做完这些事至少需要用多少分钟．
<gadget id="calculator">15 + 2</gadget>
<output>17</output>

<result>17</result>