Question

Книга в магазине подорожала на 20% потом педешевала на 10%.Если новая цена 135 сомов то найдите старую цену? ​

Answer 1

Ответ:

её старая цена 128,25..........

Answer 2

Calculation of the Old Price

To find the old price of the book, we need to reverse the process of price changes. The book first increased by 20% and then decreased by 10%. Let's calculate the old price step by step:

1. Increase of 20%: The book's price increased by 20%. This means the new price is 120% of the old price. 2. Decrease of 10%: The book's price then decreased by 10%. This means the new price is 90% of the previous price.

To find the old price, we need to divide the new price by 90% (0.9) and then multiply it by 100% (1) to convert it back to the old price.

Let's calculate it using the given information:

New price: 135 soms Increase: 20% Decrease: 10%

1. Increase of 20%: - New price = 120% of the old price - 135 = 1.2 * old price

2. Decrease of 10%: - New price = 90% of the previous price - 135 = 0.9 * (1.2 * old price)

Now, let's solve the equation to find the old price:

0.9 * (1.2 * old price) = 135

To isolate the old price, we divide both sides of the equation by 0.9 * 1.2:

old price = 135 / (0.9 * 1.2)

Calculating this, we find that the old price of the book was approximately 125 soms.

Please note that the search results did not provide any relevant information for this specific calculation.