Xiao Hong had already read 40 pages of the book, which was exactly two-fifths of the book. How many pages were left?
If Xiao Hong had already read 40 pages of a book, which was two-fifths of the book, then Xiao Hong had already read 20% or 0.2 times the book. How many pages are there in the book? You can divide the number of pages by the number of pages in the book: (100% - 02) / 100% = 90% Therefore, Little Red only had 10 pages left.
Xiao Xiao was reading a 150-page book. She had already read two-fifths of the book. How many pages were left?
If Xiaoxiao had already read two-fifths of a 150-page book, then she had already read 150 × 2/5 = 60 pages. The remaining pages were 150 - 60 = 90 pages. Hence, Xiao Xiao still had 90 pages to read.
Xiao Xiao read a science book on the first day and read 30 pages, which is two-fifths of the book. How many pages has Xiao Xiao not read yet?
Your question is a little unclear. Can you provide more context information? For example, what is the "book" that you are referring to and why did Xiaoxiao read it? This way, I can better help you answer your questions.
Xiao Hong read a book and read 15 pages a day. After four days, she still had three-fifths of the book left. How many pages was this book?
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.
A book had 170 pages. Xiaowen had read two-fifths of it. How many pages were left?
Xiao Hong read a book and read 15 pages a day. After 4 days, she read three-fifths of the book. How many pages does this book have?
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.
Xiao Ming was reading a 200-page storybook. He had already read two-fifths of the book and had 10 more pages. How many pages were left?
Xiao Ming had already read two-fifths of a 200-page storybook, which was 10 pages more. 200 pages × 2/5 + 10 pages = 40 pages The remaining pages were: 200 - 40 pages = 160 pages Therefore, Little Ming still had 160 pages left.
Zhang Bin was reading a book. He had already read 39 pages, and there were still two-fifths left. How many pages were there in this book?
This book had: 39 + 2/5 = 39 + 06 = 406 pages. Because the number of pages in a book must be an entire number, the decimals needed to be rounded to the nearest whole number. Therefore, the book had a total of 40 pages.
Xiao Xiao was reading a 150-page book. She had read two-fifths of the book in four days. How many pages were left?
Xiao Xiao read a 150-page book for four days and read two-fifths of the book. Xiaoxiao reads 1/5/4 = 1/10 of the book every day The book had 150 pages, so Xiaoxiao still needed to read pages 1 - 1/5 - 1/10 = 4/5. And because Xiaoxiao had already read two-fifths of the book, there were still four to five pages left. Hence, Xiao Xiao still needed to read 2/5 pages.
Xiao Ming is reading a 150-page storybook. He has already read two-fifths of the book. How many pages are left?
Xiao Ming had already read two-fifths of a 150-page storybook, so he had already read 150 × 2/5 = 60 pages. Therefore, there were still 150 - 60 = 90 pages left in the storybook.
Little Light had a book. He read 18 pages on the first day, which was two-fifths of the book. How many pages were left?
This book was left: Two-fifths of the book is 18 pages, 2/5 = 9 pages (with two decimals) Therefore, there were still nine pages left in the book.