In a book, the number of pages read is three times the number of pages not read. Given that 60 pages have been read, how many pages are there in this book?
一本书，已读的页数是没读的页数的3倍．已知读了60页，这本书有多少页？
<gadget id="calculator">1 + 3</gadget>
<output>4</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">60 / (3/4)</gadget>
<output>80</output>

<result>80</result>