Xiaohua reads a book and reads 16 pages every day. After 5 days, there are still (3/5) of the whole book left. How many pages is this book.
小华看一本书，每天看16页，5天后还剩全书的(3/5)没看．这本书是多少页．
<gadget id="calculator">16 * 5</gadget>
<output>80</output>

<gadget id="calculator">3 / 5</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">80 / (2/5)</gadget>
<output>200</output>

<result>200</result>