Xiao Ming reads a story book, reads 25% and 10 pages of the whole book on the first day, and reads the rest (2/5) on the second day. At this time, the ratio of the number of pages that have been read to the number of pages that have not been read is 4: 3. How many pages does this book have?
小明看一本故事书，第一天看了全书的25%又10页，第二天看了余下的(2/5)，这时，已看的与未看的页数之比为4：3，这本书共有多少页？
<gadget id="calculator">3 / 140</gadget>
<output>3/140 = around 0.021429</output>

<gadget id="calculator">6 / (3/140)</gadget>
<output>280</output>

<result>280</result>