Math problem: The fruit shop has a batch of fruits, which sold for 25% and then brought in 260 kg. At this time, the ratio of the total number of fruits to the original is 7:5. How many kilograms of fruit are there in the fruit shop? Suppose: the fruit shop used to have x kilograms of fruit.

Title display: x * (1-25%)+260 = x * 7/5.

The solution is X=400 kg.

Problem-solving process: The original X kilograms of fruit has been sold for 25%, leaving 1-25% = 75%. Later, there was a purchase of 260 kg, and now the fruit shop has fruit X * (1-25%)+260. From the meaning of the question, we can also know that the ratio of the total number of fruits to the original is 7:5, so the total number of fruits now is 7/5 times that of X, which is x*7/5. The above equation is obtained when the two formulas are equal.