Xiaole and Xiaowen read "Dad in the Pocket" at the same time. Xiaole plans to finish it in 12 days. He reads 3 pages more than Xiaowen every day, so he will finish it 4 days earlier than Xiaowen. This book How many pages are there?
小乐和小文同时看一本《装在口袋里的爸爸》小乐计划用12天看完，他每天比小文多看3页，所以会比小文提前4天看完，这本书一共有多少页？
<gadget id="calculator">12 - 4</gadget>
<output>8</output>

<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(1/8) - (1/12)</gadget>
<output>1/24 = around 0.041667</output>

<gadget id="calculator">3 / (1/24)</gadget>
<output>72</output>

<result>72</result>