Question

Сделайте эти задачи с условием пожалуйста 1.Шкаф стоил 4 800р.Сначала его цену снизили на 10%, а потом новую цену повысили на 25%.Какой стала цена шкафа после этих изменений?На сколько процентов изменилась начальная цена шкафа?2.К 620г 40%-го раствора соли долили 180г воды.Найдите процентное содержание соли в новом растворе.3.На сколько процентов уменьшится число при уменьшении его в 2,5 раза?

Answer 1

Ответ:

Пошаговое объяснение:

Answer 2

1.шкаф - 4800 р.

снизили - на 10%

повысили - на 25%

Решение:

1) 25 - 10 = 15% (на 15% повысили)

2) 4800 - 100%

    х - 15%

х = 4800 * 15/100 = 720 р. (это типо чему равно 15%)

3) 4800 + 720 = 5520 р.

ОТВЕТ: Шкаф стал стоить 5520 рублей.

3. Число уменьшится на 250%

я не знаю ответ на 2-е. извиняйте(((

Answer 3

Task 1: Шкаф стоил 4 800р. Сначала его цену снизили на 10%, а потом новую цену повысили на 25%. Какой стала цена шкафа после этих изменений? На сколько процентов изменилась начальная цена шкафа?

To solve this problem, we'll start with the initial price of the cabinet, which is 4,800 rubles.

First, the price was reduced by 10%. To find the new price after the reduction, we can calculate 90% of the initial price: 4,800 * 0.9 = 4,320 rubles.

Next, the new price was increased by 25%. To find the final price after the increase, we can calculate 125% of the reduced price: 4,320 * 1.25 = 5,400 rubles.

Therefore, the final price of the cabinet after these changes is 5,400 rubles.

To calculate the percentage change in the initial price of the cabinet, we can use the formula: ((final price - initial price) / initial price) * 100.

Let's calculate it: ((5,400 - 4,800) / 4,800) * 100 = 12.5%.

So, the initial price of the cabinet changed by 12.5%.

Task 2: К 620г 40%-го раствора соли долили 180г воды. Найдите процентное содержание соли в новом растворе.

To solve this problem, we'll calculate the amount of salt in the new solution and then find its percentage.

We start with a 40% salt solution weighing 620 grams. This means that 40% of the solution's weight is salt, and the remaining 60% is water.

The amount of salt in the original solution is: 620g * 0.4 = 248g.

180 grams of water is added to the solution, but the amount of salt remains the same.

The total weight of the new solution is: 620g + 180g = 800g.

To find the percentage of salt in the new solution, we divide the amount of salt by the total weight and multiply by 100: (248g / 800g) * 100 ≈ 31%.

Therefore, the percentage of salt in the new solution is approximately 31%.

Task 3: На сколько процентов уменьшится число при уменьшении его в 2,5 раза?

To find the percentage decrease when a number is reduced by a certain factor, we can use the formula: ((initial value - final value) / initial value) * 100.

In this case, the number is being reduced to 2.5 times its original value.

Let's assume the initial value is 100.

The final value, after reducing it to 2.5 times, would be: 100 / 2.5 = 40.

To find the percentage decrease, we can use the formula: ((100 - 40) / 100) * 100 = 60%.

Therefore, the number decreases by 60% when it is reduced to 2.5 times its original value.

I hope this helps! Let me know if you have any further questions.