Question

✅14. Школьники решили посадить на субботнике 200 деревьев. В первый час работы было посажено 54 дерева. Сколько % всех деревьев они успели посадить за это время? ✅15. После увеличения цена на мобильный телефон на 10% он стал стоить 6600 руб. Определите первоначальную цену телефона. ✅16. После снижения цены на товар на 30% он стал стоить 4200рублей. Найдите его первоначальную цену. ✅17. Банкомат берет 3% от положенной в него суммы денег. Сколько денег положить в банкомат, чтобы на счету оказалось 776 рублей? ✅18. Банкомат берет комиссию в 2% от внесенной суммы денег. Сколько денег необходимо опустить в банкомат, чтобы на счет пришло 196рублей? ✅19. После снижения цены на 15% товар стал стоить 255 рублей. Найдите начальную его цену. ✅20. После увеличения стоимости брюк на 5% они стали стоить 2310руб. Какова была их начальная стоимость?✅21. В школе 800 учеников. Из них 120 человек приняли участие в лыжной гонке. сколько процентов всех учеников школы приняло участие в гонке? Пожалуйста помогите

Answer 1

✅14.Будет 27 процентов
Док-ва: 54*100%/200=27%
✅15.6600:110%*100%=6000(руб)-первоначальная цена телефона.Можно ещё так: 6600:1,1=6000(руб)  (1,1- это 110%)
✅16.100-30=70% новая цена товара
70%=0,7
4200:0,7=6000 стоил товар
✅17.100% - x рублей.

97% - 776 рублей. (3% считается как комиссия).

Перемножаем крест на крест, и находим искомую сумму.

x=(100*776)/97=800 рублей. Сумма, которую нужно положить в банкомат, чтобы 776 рублей пришло на счет.То есть, три процента от 800 рублей, составляют 24 рубля.

Ответ: 800 рублей необходимо положить в банкомат, чтобы на счету оказалось 776 рублей.

✅18.200 рублей т.к
200:100*2=4
200-4=196 рублей
✅19. 100% - ? руб.

85% - 255 руб.

Решим это пропорцией:

100*255/85=300 руб.

Ответ: 300 рублей стоил товар до снижения цены.

✅20.2310=105%
2310/105=22р(1%)
22*5=110р(5%)
2310-110=2200

Answer 2

Answer 14:

To find out how many trees the students managed to plant in the given time, we need to calculate the percentage of trees planted in the first hour and then use that percentage to find the total number of trees.

The percentage of trees planted in the first hour can be calculated by dividing the number of trees planted in the first hour (54) by the total number of trees the students planned to plant (200) and then multiplying by 100.

Percentage of trees planted in the first hour = (54 / 200) * 100 = 27%

To find the total number of trees planted, we can use the calculated percentage. We multiply the percentage (27%) by the total number of trees planned to be planted (200).

Total number of trees planted = 27% of 200 = 0.27 * 200 = 54 trees

Therefore, the students managed to plant 54 trees in the given time.

Answer 15:

To determine the initial price of the mobile phone before the 10% increase, we can use the given information.

Let's assume the initial price of the phone is x.

According to the information, after a 10% increase, the phone now costs 6600 rubles.

We can set up the following equation to solve for x:

x + 0.10x = 6600

Simplifying the equation:

1.10x = 6600

Dividing both sides of the equation by 1.10:

x = 6000

Therefore, the initial price of the mobile phone was 6000 rubles.

Answer 16:

To find the initial price of the product before the 30% decrease, we can use the given information.

Let's assume the initial price of the product is x.

According to the information, after a 30% decrease, the product now costs 4200 rubles.

We can set up the following equation to solve for x:

x - 0.30x = 4200

Simplifying the equation:

0.70x = 4200

Dividing both sides of the equation by 0.70:

x = 6000

Therefore, the initial price of the product was 6000 rubles.

Answer 17:

To determine the amount of money to deposit in the ATM to have 776 rubles in the account, we need to account for the 3% fee charged by the ATM.

Let's assume the amount of money to deposit is x.

According to the information, the final amount in the account after the fee is 776 rubles.

We can set up the following equation to solve for x:

x - 0.03x = 776

Simplifying the equation:

0.97x = 776

Dividing both sides of the equation by 0.97:

x = 800

Therefore, the amount of money to deposit in the ATM to have 776 rubles in the account is 800 rubles.

Answer 18:

To determine the amount of money to withdraw from the ATM to have 196 rubles in the account after a 2% commission, we can set up the following equation:

Let's assume the amount of money to withdraw is x.

According to the information, the final amount in the account after the commission is 196 rubles.

We can set up the following equation to solve for x:

x - 0.02x = 196

Simplifying the equation:

0.98x = 196

Dividing both sides of the equation by 0.98:

x = 200

Therefore, the amount of money to withdraw from the ATM to have 196 rubles in the account is 200 rubles.

Answer 19:

To find the initial price of the product before the 15% decrease, we can use the given information.

Let's assume the initial price of the product is x.

According to the information, after a 15% decrease, the product now costs 255 rubles.

We can set up the following equation to solve for x:

x - 0.15x = 255

Simplifying the equation:

0.85x = 255

Dividing both sides of the equation by 0.85:

x = 300

Therefore, the initial price of the product was 300 rubles.

Answer 20:

To determine the initial cost of the pants before the 5% increase, we can use the given information.

Let's assume the initial cost of the pants is x.

According to the information, after a 5% increase, the pants now cost 2310 rubles.

We can set up the following equation to solve for x:

x + 0.05x = 2310

Simplifying the equation:

1.05x = 2310

Dividing both sides of the equation by 1.05:

x = 2200

Therefore, the initial cost of the pants was 2200 rubles.

Answer 21:

To find the percentage of students who participated in the ski race out of the total number of students in the school, we can use the given information.

According to the information, there are 800 students in the school, and 120 students participated in the ski race.

We can calculate the percentage by dividing the number of students who participated (120) by the total number of students (800) and then multiplying by 100.

Percentage of students who participated = (120 / 800) * 100 = 15%

Therefore, 15% of all students in the school participated in the ski race.