Question

На трех полках стоит 104 книги.Из них 68 книг-на второй и третьей полках, а остальные-на первой, причем на первой полке стоит на 9 книг больше, чем на третьей.Сколько книг стоит на второй полке? дам 30 баллов

Answer 1

1). 104-68=36 книг на первой полке
2). 36-9=27 книг на третей полке
3). 36+27=63 книги на первой и третьей полках вместе
4). 104-63=41 книга на второй полке

Answer 2

Problem Analysis

We are given that there are a total of 104 books on three shelves. Out of these, 68 books are on the second and third shelves combined, and the rest are on the first shelf. Additionally, there are 9 more books on the first shelf than on the third shelf. We need to determine the number of books on the second shelf.

Solution

Let's assume the number of books on the third shelf is x. Since there are 9 more books on the first shelf than on the third shelf, the number of books on the first shelf would be x + 9.

According to the given information, the total number of books on the second and third shelves combined is 68. Therefore, we can write the equation:

x + (x + 9) = 68

Simplifying the equation, we get:

2x + 9 = 68 2x = 68 - 9 2x = 59 x = 59 / 2 x = 29.5

Since the number of books cannot be a decimal, we can conclude that there are 29 books on the third shelf.

To find the number of books on the second shelf, we can substitute the value of x into the equation for the number of books on the first shelf:

x + 9 = 29 + 9 = 38

Therefore, there are 38 books on the second shelf.

Answer

There are 38 books on the second shelf.