Xiaowen is 7 years old and her mother is 35 years old. How old is Xiaowen's mother eight times as old as Xiaowen?

First, let's assume the unknown. When Xiaowen's age is X, her mother's age is 28+X. From the meaning of the question, we can get 28+X = 8x, and X=4.

Second, when the mother's age is eight times that of Xiaowen, then the age difference of 28 should be seven times that of Xiaowen, and 28/7=4.