Xiaohong reads a story book. She reads (1/3) of the book on the first day, reads 45 pages on the second day, and leaves 15 pages unread. How many pages are there in this book?
小红读一本故事书，第一天读了这本书的(1/3)，第二天读了45页，还剩下15页没有读．这本书一共多少页？
<gadget id="calculator">45 + 15</gadget>
<output>60</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">60 / (2/3)</gadget>
<output>90</output>

<result>90</result>