Da Mao reads a math fairy tale book, the ratio of the number of pages he has read to the number of pages he has not read is 1:5, if he reads 10 more pages, the number of pages he has read accounts for 25% of the total number of pages, how many pages are there in this book ?
大毛看一本数学童话书，已看页数与未看页数的比是1：5，如果再看10页，这时已看页数占总页数的25%，这本书共有多少页？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

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

<gadget id="calculator">1 + 5</gadget>
<output>6</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/4) - (1/6)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">10 / (1/12)</gadget>
<output>120</output>

<result>120</result>