Fangfang reads a storybook and reads 15 pages, which is exactly (3/5) of the whole book. How many pages does this book have?
芳芳看一本故事书，看了15页，正好是全书的(3/5)，这本书有多少页？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">15 / (3/5)</gadget>
<output>25</output>

<result>25</result>