## Xiao Hong read a book. On the first day, she read & nbsp; 15 of the whole book, and on the second day, she read & nbsp; 38 of the whole book. At this time, there are 51 Pages left. How many pages are there in this book?

fifty-one ÷ （1-15-38）=51 ÷ 1740 = 120 (pages); A: the book has 120 pages

I read a story book one after another. On the first day, I read one third of the whole book, and on the second day, I read half of the whole book

The ratio of the number of pages not read to the number of pages in this book is ()

5:1 1:6

Xiao Ming read a book, the first day read 13 of this book, the next day read 13 of this book & nbsp; 12. Finish the remaining 10 pages on the third day. How many pages does the book have?

10 ÷ （1-13-12）=10 ÷ A: there are 60 pages in this book

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