Little Red read a book and read 15 pages a day. After four days, there were still three-fifths of the book that she had not read. How many pages was this book?

Suppose the book has x pages: Little Cong read 15 pages a day for four days, a total of 4×15=60 pages. The total number of pages in the book is x, so: 60÷(1+3/5)=x÷5 The solution was:x=60×5 div3 =600 div3 =200 pages. Therefore, the book had a total of 200 pages.

Xiao Ming reads a book every day, reads 15 pages, and after 4 days, there are still 3/5 of the book left. How many pages does this book have? Assuming that the book has a total of $x$pages, then the number of pages that Xiao Ming reads in 4 days is $15,4 = 60$pages. The remaining pages are 3/5 of the book's worth, so there are: $$ 60 \div (3/5) = 12 $$ So the book has a total of $12$pages.

Let's say the book has $x$pages. Reading 15 pages a day, it would take Xiaohong $x$days to finish reading this book. The remaining pages were three-fifths of the book, which was $025x$. According to the question, it would take Xiaohong four days to finish reading this book. Therefore, we can write the equation: $$ x + 025x = 025 \times (x+4) $$ Solve this equation: $$ x = 30 $$ So this book has 30 pages.

Little Red reads a book 15 pages a day, and after 4 days, there is still 3/5 of the book left. We can assume that this book has x pages. According to the question, Little Red had read a total of $4/times 15 = 60$pages in 4 days. The remaining pages are 3/5 of the book, so there are: $$ 60\div 3/5=24 $$ Therefore, the book had 24 pages.

Assuming that the book has a total of $x$pages, then Little Red has read $x/times 15$pages in 4 days. The remaining pages are 3/5 of the book's worth, so there are: $$x <times 15><times 3/5>= Total pages $$ Solve this equation: $$x = \frac{total pages}{15} = \frac{1200}{15} = 80$$ Therefore, the book had a total of 80 pages.

This book had a total of 15 × 4 = 60 pages.

Assuming that the book has a total of $x$pages, how many pages has Xiaohong read in 4 days? Based on the 15 pages she read every day, she read a total of $15,4 =$60 pages. Then she read three-fifths of the book, which means that she only read the $3/5 part of the book. Therefore, we can write the equation: $$60 = 3/5 \times x$$ To solve this equation, you can get $x = 60 times 5/3 = 100$. Therefore, the book had a total of 100 pages.

Let's say the book has $x$pages. Reading 15 pages a day meant that you could read $4/times 15 = 60$pages in 4 days. The rest of the content that he did not read was four-fifths of the book, which was $x/div4 = 5x/4$. Solve the equation to get $x = 40$. So this book has 40 pages.

Kobayashi read one-tenth of the book on the first day. On the second day, he saw four-fifths of the first day, which was 4/5 × 1/10 = 8/10. Therefore, the remaining pages were 1-8/10 = 2/10 of the entire book. There were 123 pages left. Therefore, this book had a total of 123 + 2/10 = 123 + 2 × 1/10 = 123 + 2/5 = 125 pages.

Assuming that the book has a total of $x$pages, then according to the question, Kobayashi reads $16$pages a day and finishes the book in 5 days. In this way, Kobayashi needed to read $16/div2 = 8$pages in the remaining $2/5$. Because Kobayashi had watched it for a total of $5$days, he still needed to watch it for $5 - 4 = 1$days. Therefore, Kobayashi still needed to read $8$pages of this book, a total of $x$pages. According to the meaning of the question, this book has a total of $x$pages. Kobayashi reads $16$pages a day and finishes reading this book in 5 days. Therefore, there is the following equation: $$8 = \frac{x}{2} + \frac{x}{5} + 8$$ To simplify it: $$x = 100$$ So the book had 100 $pages.