Xiao Ming finished reading a book in two days. The number of pages he read on the first day was 50% more than that on the second day, and the number of pages he read on the second day was 50 pages less than that on the first day. How many pages in this book are there in total?
小明两天看完一本书，第一天看的页数比第二天多50%，第二天看的页数比第一天少50页，这本书共多少页．
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">50 / (1/2)</gadget>
<output>100</output>

<gadget id="calculator">100 + 50</gadget>
<output>150</output>

<gadget id="calculator">100 + 150</gadget>
<output>250</output>

<result>250</result>