When Xiaoyong reads an extracurricular book, the number of pages he has read is 28 pages less than (3/4) the total number of pages in the book, and the ratio of the number of pages he has read to the number of pages he has not read is 2:3. How many pages does this extracurricular book have?
小勇看一本课外书，已看的页数比这本书总页数的(3/4)少28页，已看的页数与未看的页数比是2：3．这本课外书共有多少页？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">2 + 3</gadget>
<output>5</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(3/4) - (2/5)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">28 / (7/20)</gadget>
<output>80</output>

<result>80</result>