For a book, Lele read (1/4) of the whole book on the first day, and the ratio of the number of pages read on the second day to the number of pages read on the first day is 4:3. Two days later, there are still 50 pages left to read. How many pages are there in this book?
一本书，乐乐第一天读了全书的(1/4)，第二天读的页数与第一天读的页数的比是4：3．两天后还剩下50页没读，这本书一共有多少页？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">4 / 3</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">(1/4) * (4/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/4) - (1/3)</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">50 / (5/12)</gadget>
<output>120</output>

<result>120</result>