Question

Вася и Петя читают один и тот же рассказ. Вася прочитывает за 1 час 30 страниц, а Петя 40 страниц. Они начали читать одновременно, и Петя закончил на полчаса раньше, чем Вася. Сколько страниц занимает рассказ? (Учитель сказал что на логику, без уравнения)

Answer 1

В книге 60 страниц, за час вася прочитает 30 стр, а за 2 часа 60 стр, а петя. 60 стр прочитает за 1,5 часа

Answer 2

Problem Analysis

We are given that Vasya and Petya are reading the same story. Vasya reads 30 pages in 1 hour, while Petya reads 40 pages in 1 hour. Petya finishes half an hour earlier than Vasya. We need to determine the total number of pages in the story.

Solution

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

We know that Vasya reads 30 pages in 1 hour, so Vasya's reading speed is 30 pages/hour.

We also know that Petya reads 40 pages in 1 hour, so Petya's reading speed is 40 pages/hour.

Since Petya finishes half an hour earlier than Vasya, we can set up the following equation:

Petya's reading time = Vasya's reading time - 0.5 hours

To find the reading time, we can use the formula:

Reading time = Number of pages / Reading speed

For Petya, the reading time is x pages / 40 pages/hour.

For Vasya, the reading time is x pages / 30 pages/hour.

Using the equation above, we can write:

x / 40 = (x / 30) - 0.5

Simplifying the equation:

x / 40 = (x - 15) / 30

Cross-multiplying:

30x = 40(x - 15)

Expanding:

30x = 40x - 600

Simplifying:

10x = 600

Solving for x:

x = 60

Therefore, the story has 60 pages.

Answer

The story contains 60 pages.