Xiaohong reads a book. On the first day, she reads a quarter of the whole book, but she reads one-fifth less than on the second day. There are 49 pages left. How many pages is this book?
小红看一本书，第一天看了全书的四分之一，比第二天少看了五分之一，剩下49页，这本书多少页？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(1/4) / (4/5)</gadget>
<output>5/16 = around 0.3125</output>

<gadget id="calculator">1 - (1/4) - (5/16)</gadget>
<output>7/16 = around 0.4375</output>

<gadget id="calculator">49 / (7/16)</gadget>
<output>112</output>

<result>112</result>