A batch of paper needs to be bound into a teacher’s textbook, each with 50 pages, and 90 books can be bound; if it is bound into a student’s exercise book, each 30 pages, how many books can be bound? (answer in two ways)
一批纸要装订成教师备课本，每本50页，可装订90本；若装订成学生练习本，每本30页，能装订多少本？(用两种方法解答)
<gadget id="calculator">90 / 30</gadget>
<output>3</output>

<gadget id="calculator">50 * 3</gadget>
<output>150</output>

<result>150</result>