Question

Мама положила на тарелку абрикосы. После того как брат взял 1/7 часть всех абрикосов, а сестра 1/4 остатка, на тарелке осталось еще 18 абрикосов. Сколько абрикосов положила мама на тарелку?

Answer 1

Пусть х абрикосов мама положила..
тогда брат взял х*1\7
после этого осталось в тарелке х-х*1\7=х(1-1\7)=х*6\7
И от этого остатка сестра взяла 1\4, то есть 18 абрикосов это 3\4 от х*6\7
Получаем уравнение
3\4*х*6\7=18
9\14*х=18
х=18 : 9\14
х= 18* 14 : 9
х=28 мама положила на тарелку

Answer 2

1/7 +( 1/4 от  6/7) + х = 1 
1/7 +6/28 +х =1
10/28 +х =1
х =18/28 =9/14
9/14 =18
находим целое по части:
18/9*14= 28 (аб) -было.

Answer 3

Problem Analysis

We are given that a mother put some apricots on a plate. After the brother took 1/7 of all the apricots and the sister took 1/4 of the remaining apricots, there were 18 apricots left on the plate. We need to determine how many apricots the mother initially put on the plate.

Solution

Let's assume that the mother initially put x apricots on the plate.

According to the problem, the brother took 1/7 of all the apricots, which is (1/7)x apricots.

After the brother took his share, the remaining apricots on the plate are x - (1/7)x = (6/7)x.

Next, the sister took 1/4 of the remaining apricots, which is (1/4)(6/7)x = (3/14)x apricots.

After the sister took her share, the remaining apricots on the plate are (6/7)x - (3/14)x = (9/14)x.

According to the problem, there were 18 apricots left on the plate, so we can set up the equation:

(9/14)x = 18

To find the value of x, we can solve this equation:

(9/14)x = 18
x = (18 * 14) / 9
x = 28

Therefore, the mother initially put 28 apricots on the plate.

Answer

The mother initially put 28 apricots on the plate.