Xiaoqing finished reading a story book this week. She read 13 pages on the first day, an average of 17 pages per day in the next three days, and 41 pages in the last three days. How many pages of story books does she read on average every day?
小晴本周读完了一本故事书．第一天她读了13页，接下来的三天平均每天读了17页，最后三天读了41页．她平均每天读故事书多少页．
<gadget id="calculator">17 * 3</gadget>
<output>51</output>

<gadget id="calculator">13 + 51 + 41</gadget>
<output>105</output>

<gadget id="calculator">105 / 7</gadget>
<output>15</output>

<result>15</result>