60% of a book has been read, and there are 60 pages left. How many pages are there in this book?
一本书看了它的60%，还剩60页，这本书有多少页．
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">60 / (2/5)</gadget>
<output>150</output>

<result>150</result>