Question

Из числа участников кружка домбристов лишь одна третья умеют играть на домбристов.через неделю ещё 6участников научились играть на этом инструменте. после этого количество не умеющих играть на домбристов.через составило 10%всех участников кружка .сколько человек посещают кружок домбристов?А.20человек;В24человек;С.25человек;Д.18человек человек решите задачу

Answer 1

20 человек,ответ первый

Answer 2

Problem Analysis

We are given that initially, only one-third of the participants in a dombra club can play the dombra. After a week, six more participants learn to play the instrument. Following this, the number of participants who cannot play the dombra decreases to 10% of the total number of participants in the club. We need to determine the total number of people attending the dombra club.

Solution

Let's assume the total number of participants in the dombra club is x.

Initially, only one-third of the participants can play the dombra, which means x/3 participants can play the dombra.

After a week, six more participants learn to play the dombra. So the number of participants who can play the dombra becomes (x/3) + 6.

The number of participants who cannot play the dombra after a week is 10% of the total number of participants, which is 0.1x.

According to the given information, we can set up the following equation:

(x/3) + 6 = 0.1x

Let's solve this equation to find the value of x.

(x/3) + 6 = 0.1x

Multiplying both sides of the equation by 3 to eliminate the fraction:

x + 18 = 0.3x

Subtracting 0.3x from both sides:

18 = 0.3x - x

Simplifying:

18 = 0.7x

Dividing both sides by 0.7:

x = 18 / 0.7

Calculating:

x ≈ 25.71

Since the number of participants must be a whole number, we round up to the nearest whole number:

x = 26

Therefore, the total number of people attending the dombra club is 26.

Answer

The correct answer is C. 25 people.