Question

На трёх этажах дома проживают 70 человек.На первом и на втором этажах 46 человек,на втором и на третьем 50 человек.Сколько человек проживают на каждом этаже Решите задачу двумя способами

Answer 1

1)70-46=24(ч) на третьем этаже
2)50-24=26(ч) на втором этаже
3)46-26=20(ч) на первом этаже

Answer 2

Problem Analysis

We are given that there are 70 people living in a three-story building. On the first and second floors, there are 46 people, and on the second and third floors, there are 50 people. We need to determine how many people live on each floor using two different methods.

Method 1: Using Algebra

Let's assume that the number of people living on the first floor is represented by x, the number of people living on the second floor is represented by y, and the number of people living on the third floor is represented by z.

From the given information, we can write two equations:

1. Equation 1: x + y = 46 (since there are 46 people on the first and second floors) 2. Equation 2: y + z = 50 (since there are 50 people on the second and third floors)

To solve these equations, we can use substitution or elimination.

Using substitution, we can solve Equation 1 for x and substitute it into Equation 2:

x = 46 - y

Substituting this value of x into Equation 2:

(46 - y) + y = 50 46 + y - y = 50 46 = 50

This equation is not possible, which means there is no solution using this method.

Method 2: Using a System of Equations

Let's try solving the problem using a system of equations.

We have the following equations:

1. Equation 1: x + y = 46 2. Equation 2: y + z = 50

To solve this system, we can use the method of substitution or elimination.

Using substitution, we can solve Equation 1 for x and substitute it into Equation 2:

x = 46 - y

Substituting this value of x into Equation 2:

(46 - y) + z = 50

Rearranging this equation:

z = 50 - (46 - y) z = 50 - 46 + y z = 4 + y

Now we have a system of two equations:

1. Equation 1: x + y = 46 2. Equation 3: z = 4 + y

Substituting Equation 3 into Equation 1:

x + y = 46 (4 + y) + y = 46 4 + 2y = 46 2y = 46 - 4 2y = 42 y = 42 / 2 y = 21

Substituting this value of y into Equation 3:

z = 4 + y z = 4 + 21 z = 25

Therefore, we have found the following values:

- Number of people on the first floor (x): Not determined - Number of people on the second floor (y): 21 - Number of people on the third floor (z): 25

Summary

Using the given information, we have determined that there are 21 people living on the second floor and 25 people living on the third floor. However, we were unable to determine the number of people living on the first floor using the given information.

Please let me know if there is anything else I can help you with!