Xiaofang reads a "Grimm's Fairy Tale", read the whole book (2/5) on the first day, and read the whole book (1/5) on the second day, there are still 72 pages left, how many pages does this fairy tale book have? ?
小芳看一本«格林童话»，第一天看了全书的(2/5)，第二天看了全书的(1/5)，还有72页没看，这本童话书共有多少页？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

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

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

<gadget id="calculator">72 / (2/5)</gadget>
<output>180</output>

<result>180</result>