Question

Ученик прочитал 1/8 книги , а затем 2/7 оставшейся части, После этого он заметил , он заметил , что прочитал на 18 страниц меньше, чем ему осталось прочитать , Сколько страниц в книге ?

Answer 1

Х стр- всего в книге 1/8Х-прочитал Х-1/8Х=7/8Х -осталось прочитать 2/7 * 7/8Х=1/4Х -прочитал во 2й раз 1/8Х +1/4Х=3/8Х - прочитал всего Х-3/8Х=5/8Х - осталось прочитать 3/8Х меньше, чем 5/8Х на 18 сост. ур-е : 3/8Х+18=5/8Х 18=5/8Х-3/8Х =2/8Х=1/4Х 18=1/4Х Х=18:1/4= 18*4=72 Ответ: в книге 72 стр

Answer 2

Problem Analysis

The problem states that a student read 1/8 of a book and then read 2/7 of the remaining part. After that, the student noticed that they had read 18 pages less than what was left to read. We need to determine the total number of pages in the book.

Solution

Let's assume the total number of pages in the book is x.

The student read 1/8 of the book, which is equal to (1/8) * x pages.

After reading 1/8 of the book, the student had (7/8) * x pages left to read.

The student then read 2/7 of the remaining part, which is equal to (2/7) * (7/8) * x pages.

According to the problem, the student noticed that they had read 18 pages less than what was left to read. So, we can set up the following equation:

(1/8) * x + (2/7) * (7/8) * x = (7/8) * x - 18

Simplifying the equation:

(1/8) * x + (1/4) * x = (7/8) * x - 18

Multiplying through by 8 to eliminate the fractions:

x + 2x = 7x - 144

Combining like terms:

3x = 6x - 144

Subtracting 6x from both sides:

-3x = -144

Dividing by -3:

x = 48

Therefore, the total number of pages in the book is 48.

Answer

The total number of pages in the book is 48.