There were still 125 pages left, so he had to read 125/5=25 pages every day. Therefore, he read an average of 25 pages a day.
Let's say this storybook has a total of $x$pages. Naughty had finished reading $5/7$of the total page count, which meant that he had $2/7$left. Therefore, Naughty still needed to read $40$to finish the total number of pages. According to the meaning of the question, mischievous still needs to look at $40$pages, so $x - 40$should be divided by $7$. Since $x$is the total number of pages,$x$should be greater than or equal to $40$. Therefore, we can write an equation: $$x \geq 40 + 40 \times 7 = 560$$ The solution to this equation is $x=567$. So this story book had a total of $567$pages.
The number of pages in a storybook can be expressed as $x$, so the total number of pages is $x \times 3/5$. Since there were still 36 pages to read, the total number of pages in the storybook plus these 36 pages was $x/times 3/5 + 36$. And because the book had a total of $x$pages, the equation could be listed: $$x \times 3/5 + 36 = x$$ If you solve this equation, you get $x=300$. Therefore, the story book had a total of $300$pages.
Xiao Ming needed to finish reading the remaining 260 pages in 5 days, so he needed to read 260 pages per day divided by 5 days = 52 pages.
Xiao Ming had already read 54 pages and was reading 8 pages a day. Therefore, he still needed 8 × 7 = 56 days to finish reading the remaining pages.
This story book had a total of $90+170=260$pages.
Xiaolan had already read 2/3 of the total number of pages in the book, so she had already read (2/3) × 240 = 80 pages. The remaining pages were 240 - 80 = 160 pages. Therefore, there were still 160 pages left to read.
For the remaining five days, he would need to read 180 pages- 80 pages = 100 pages every day. Therefore, he read an average of 100 pages a day.
The remaining 5 days need to read 180 pages/5 = 36 pages/day Therefore, Xiaoxiao needed to read 36 pages on average every day.