Xiao Ming can finish a book in 12 days, but Xiao Fang can finish it in 3 days longer than Xiao Ming, and Xiao Ming can read 3 pages more than Xiao Fang every day. How many pages does this book have.
一本书，小明12天可以看完，而小芳要比小明多3天看完，小明每天比小芳多看3页．这本书有多少页．
<gadget id="calculator">3 / 3</gadget>
<output>1</output>

<gadget id="calculator">12 + 3</gadget>
<output>15</output>

<gadget id="calculator">12 * 1 * 15</gadget>
<output>180</output>

<result>180</result>