Li Jing reads a book with more than 50 pages, and reads (1/2) more every day than the day before, and reads the whole book after three days. How many pages did Li Jing read on the first day? (I read the whole page every day)
李晶看一本50多页的书，每天都比前一天多看(1/2)，三天后看完了整本书．请问第一天李晶看了多少页？(每天看的都是整页数)
<gadget id="calculator">19 * 3</gadget>
<output>57</output>

<gadget id="calculator">19 / 4</gadget>
<output>19/4 = around 4.75</output>

<gadget id="calculator">57 / (19/4)</gadget>
<output>12</output>

<result>12</result>