Question

Петя в первый день прочитал 40% книги,во второй-60% остатка,а в третий-144 страницы.Сколько страниц в книге?

Answer 1

40 - 100%
60% - ?%
1445 - ?5
1) 40 : 100 = 0,4
2) 60 : 0,4= 150
3) 150+144=294
Ответ:294 страниц в

Answer 2

1д-0,4х            )
2д-0,4х*0,6     )х
3д-144             )

0,4х+0,4х*0,6+144=х
0,8х*0,6+144=х
0,6+144=Х-0,8х
144,6=0,2Х
1446=2х
723=х
ответ:723

Answer 3

Problem Analysis

We are given the following information: - On the first day, Petya read 40% of the book. - On the second day, Petya read 60% of the remaining pages. - On the third day, Petya read 144 pages.

We need to find the total number of pages in the book.

Solution

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

On the first day, Petya read 40% of the book, which is equal to 0.4x pages.

On the second day, Petya read 60% of the remaining pages. After the first day, the remaining pages in the book would be (1 - 0.4) * x = 0.6x. So, on the second day, Petya read 0.6 * 0.6x = 0.36x pages.

On the third day, Petya read 144 pages.

Adding up the pages read on each day, we can form the equation:

0.4x + 0.36x + 144 = x

Simplifying the equation:

0.76x + 144 = x

Rearranging the equation:

0.24x = 144

Dividing both sides by 0.24:

x = 144 / 0.24

Evaluating the expression:

x = 600

Therefore, the book has a total of 600 pages.

Answer

The book has a total of 600 pages.