Question

Помогите решить задачу только с наименованиями Девочка вчера прочитала 1/3 книги,а сегодня 3/4 остатка. Ей осталось прочитать 20 страниц.Сколько всего страниц в книге?

Answer 1

X---всего страниц
$\frac{1}{3} x$---прочитала вчера
$x- \frac{1}{3} x =\frac{2}{3}x$---остаток
$\frac{2}{3} x* \frac{3}{4} = \frac{1}{2}x$ прочитали сегодня

$\frac{1}{3} x+ \frac{1}{2}x+20=X \\ X- \frac{1}{3}x- \frac{1}{2} x=20 \\ \frac{1}{6}x=20 \\ x=20* \frac{6}{1} \\ x=120$
120 стр в книге
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$1- \frac{3}{4} = \frac{1}{4}$часть книги равна 20стр
$20*4=80$стр. остаток
$1- \frac{1}{3} = \frac{2}{3}$ часть равна 80стр
$80* \frac{3}{2} =120$стр в книге

Answer 2

Problem Analysis

To solve this problem, we need to find the total number of pages in the book. We are given that the girl read 1/3 of the book yesterday and 3/4 of the remaining pages today. We also know that she has 20 pages left to read.

Solution

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

Yesterday, the girl read 1/3 of the book, which is (1/3) * x pages.

Today, she read 3/4 of the remaining pages, which is (3/4) * (x - (1/3) * x) pages.

We are given that she has 20 pages left to read. So, the equation becomes:

(3/4) * (x - (1/3) * x) = 20

To solve this equation, we can follow these steps:

1. Simplify the equation by multiplying both sides by 4/3 to eliminate the fraction:

(4/3) * (3/4) * (x - (1/3) * x) = (4/3) * 20

Simplifying further:

x - (1/3) * x = (4/3) * 20

2. Simplify the equation:

(2/3) * x = 80

3. Multiply both sides by 3/2 to isolate x:

(3/2) * (2/3) * x = (3/2) * 80

Simplifying further:

x = 120

Therefore, the total number of pages in the book is 120.

Answer

The total number of pages in the book is 120.