When Teacher Zhang reads a book, he reads an average of 20 pages a day for the first 4 days, and 63 pages in total for the next 7 days. He just finishes reading this book. How many pages does Teacher Zhang read on average every day?Assuming that the book has a total of n pages, then Teacher Zhang has read 20×4=80 pages in the past four days, leaving n-80 pages.
In the next 7 days, he read 63 pages, so the remaining pages were 63-80=-3 pages. This result is negative, which is not consistent with reality, so there is a contradiction in the hypothesis.
Therefore, this problem is not solved. Teacher Zhang reads an average of 80 pages a day, but he has read 20 pages in the past four days, so he still needs to read another 40 pages to finish the book.
Xiao Dong read a storybook. He read 68 pages in the first four days and 72 pages in the next three days. How many pages does Xiao Dong read on average every day?Assuming that the total number of pages Xiao Dong read every day was constant, then the average number of pages he read every day could be calculated by calculating the total number of pages in the first 4 days and the last 3 days.
The total number of pages read in the first four days was 68, so Xiao Dong had read a total of 68 pages in these four days.
The total number of pages he read in the next three days was 72 pages, so Xiao Dong read a total of 72 pages in these three days.
Therefore, Xiao Dong had read a total of 68 + 72 + 10 + 2 = 190 pages in these 8 days.
Divide the total number of pages by the total number of pages you read every day to get the answer to how many pages Xiao Dong reads on average every day:
190/8 = 225 pages
The answer was 225 pages because Xiao Dong read an average of 225 pages a day.
The number of pages that Xiaoming reads on the first day is 20% of the whole book. The next day, he reads 20% of the remaining pages. The number of pages that he reads on the second day accounts for 100% of the total pages of the whole book.The number of pages that Xiaoming reads on the first day is 20% of the whole book. The number of pages that he reads on the second day is 20% of the remaining pages. The percentage of the number of pages that he reads on the second day can be calculated as follows:
The number of pages that Xiaoming read on the first day was 20% of the entire book. In other words, the total number of pages that Xiaoming read was:
Total pages = 20% × pages of the book = 02 × pages of the book
The number of pages that Xiao Ming read the next day was 20% of the remaining pages. In other words, the total number of pages that Xiao Ming read was:
Total pages = 20% x Remaining pages = 02 x Remaining pages
Then, the percentage of the number of pages that Xiao Ming read the next day in the total number of pages in the book can be calculated as:
The number of pages Xiao Ming read the next day divided by the total number of pages in the book × 100% = 02 divided by 08 × 100%= 25%
Therefore, the number of pages that Xiao Ming read the next day accounted for about 25% of the total number of pages in the entire book.