Question

В многоэтажном доме 231 квартира. В каждом подъезде одинаковое количество квартир и на каждом этаже одинаковое количество квартир, большее двух, но меньшее семи. Во втором подъезде есть квартира, номер которой больше 42. Сколько в доме этажей? А. 3 Б. 7 В. 11 Г. 21

Answer 1

Ответ Б) 7 т.к. всего 6 подъездов

Answer 2

Б 7 б 7 б 7 б 7 б 7 б 7 б 7

Answer 3

Question Analysis

The question asks for the number of floors in a multi-story building with 231 apartments. Each entrance has the same number of apartments, and each floor has the same number of apartments, which is greater than two but less than seven. The second entrance has an apartment with a number greater than 42. The options provided are:

A. 3 B. 7 C. 11 D. 21

To determine the number of floors in the building, we need to analyze the given information and find a solution.

Solution

Let's break down the information provided:

1. Each entrance has the same number of apartments. 2. Each floor has the same number of apartments. 3. The number of apartments on each floor is greater than two but less than seven. 4. The second entrance has an apartment with a number greater than 42.

Based on this information, we can deduce the following:

1. Since the number of apartments on each floor is the same, and the number of apartments on each floor is greater than two but less than seven, the number of apartments on each floor must be three, four, five, or six.

2. The second entrance has an apartment with a number greater than 42. This means that the first entrance does not have an apartment with a number greater than 42. Therefore, the first entrance must have apartments numbered from 1 to 42.

3. Since each entrance has the same number of apartments, and the first entrance has apartments numbered from 1 to 42, the second entrance must have apartments numbered from 43 to X, where X is the highest apartment number in the building.

4. The total number of apartments in the building is 231.

Based on this information, we can calculate the number of floors in the building:

- If each floor has three apartments, the total number of floors would be 231 / 3 = 77 floors. - If each floor has four apartments, the total number of floors would be 231 / 4 = 57.75 floors. - If each floor has five apartments, the total number of floors would be 231 / 5 = 46.2 floors. - If each floor has six apartments, the total number of floors would be 231 / 6 = 38.5 floors.

Since the number of floors must be a whole number, the only possible option is A. 3 floors.

Conclusion

Based on the given information, the multi-story building with 231 apartments has 3 floors.