Question

К осени цена на картофель понизилась сначала на 25 %, а затем еще раз понизилась на 70 %, после чего картофель стал стоить 6.3 р. за килограмм . Найдите летнюю цену картофеля.

Answer 1

Пусть х (руб.) - летняя цена картофеля, составим ур-е

х(1-25/100)(1-70/100)=6,3

х*0,75*0,3=6,3

0,225х=6,3

х=6,3:0,225

х=28 (руб.) - летняя цена картофеля

Answer 2

6.3 - это 30% (100%-70%) от предыдущей стоимости => предыдущая стоимость = 6.3/30*100

В свою очередь предыдущая стоимость - это 75% (100%-25%) от первоначальной стоимости.

Итого

x=(6.3/30*100)/75*100=28

Проверка:

28-28/100*25=21

21-21/100*70=6.3

Ответ: 28 руб.

Answer 3

Calculating the Original Price of Potatoes

To find the original price of potatoes, we can work backward from the given information. Let's start by calculating the original price before the first decrease.

The price decreased by 25% and then by 70%, and the final price is 6.3 rubles per kilogram.

Step 1: Calculate the Price Before the 70% Decrease

Let's denote the original price as x.

After the first decrease of 25%, the price becomes 75% of the original price: 0.75x

After the second decrease of 70%, the price becomes 30% of the previous price: 0.3 * 0.75x = 0.225x

Step 2: Calculate the Original Price

We know that the final price is 6.3 rubles per kilogram, which is equal to 0.225x: 0.225x = 6.3

Now, we can solve for x to find the original price.

Solving for the Original Price

To find the original price, we can use the equation: 0.225x = 6.3

Dividing both sides by 0.225: x = 6.3 / 0.225 x = 28

Conclusion

The original price of potatoes was 28 rubles per kilogram.

This calculation is based on the provided information and the subsequent calculations.