Distribute some books to a certain class of students to read. If each student is assigned 3 books, there will be 20 books left; if each student is assigned 4 books, there will be 25 books left. How many students are there in this class?
把一些图书分给某班学生阅读，如果每人分3本，则剩余20本；如果每人分4本，则还缺25本．则这个班有多少学生？
<gadget id="calculator">25 + 20</gadget>
<output>45</output>

<gadget id="calculator">4 - 3</gadget>
<output>1</output>

<gadget id="calculator">45 / 1</gadget>
<output>45</output>

<result>45</result>