The retail price of a certain commodity is 900 yuan per piece. In order to adapt to the market competition, the store decides to reduce the price by 10% and make a profit of 48 yuan. If the profit is still 20%, how much is the purchase price of this commodity?

The retail price of a certain commodity is 900 yuan per piece. In order to adapt to the market competition, the store decides to reduce the price by 10% and make a profit of 48 yuan. If the profit is still 20%, how much is the purchase price of this commodity?

Suppose the purchase price of this commodity is x yuan per piece, then: 900 × 0.9-48 = x + 20% x, the solution is: x = 635. Answer: the purchase price of this commodity is 635 yuan per piece

If the unit price of a commodity is reduced from 125 yuan to 80 yuan after two consecutive price cuts, the average percentage of each price cut is______ ．

Let X be the percentage of the average price reduction of this kind of goods. According to the equation, we get 125 (1-x) 2 = 80, and the solution is X1 = 0.2 = 20%, X2 = 1.8

In 2012, the socially necessary labor time of a commodity is one hour, and its value is expressed as 60 yuan in currency. Assuming that the labor production efficiency of the production field is increased by 20% in 2013, and the state issues 10% more currency, other conditions remain unchanged, then the value of the commodity is expressed as?

It's 55 yuan
The labor productivity of this production field is social labor productivity, and the value of goods is inversely proportional to social labor productivity. Therefore, after the labor productivity of this production field has been increased by 20% in 12 years, the value of goods is 60 / (1 + 20%) = 50 yuan. At this time, the state issues 10% more banknotes, and 50x (1 + 10%) = 55 yuan. The correct answer is B
Test point: the relationship between the value of goods and social labor productivity, the relationship between the circulation of paper money and the value of goods
Comments: This is a common calculation problem. As long as the examinee knows that the social labor productivity is inversely proportional to the value of goods, and the circulation of banknotes is directly proportional to the value of goods, it is easier to calculate. A principle that needs to be noted is that multiplication is used for direct ratio and division is used for inverse ratio
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