1. Father is 47 years old and son is 2 1 year old. Years ago, my father was three times as old as my son.

2. This year, my uncle is 2 1 year old and Xiao Qiang is 5 years old. My uncle is three times as old as Xiao Qiang.

Xiaoming is 9 years old and his mother is 39 years old. In (), her mother was exactly three times as old as Xiao Ming.

Mingming is 28 years younger than his father, and his father is five times older than Mingming this year. Yao Ming is () years old, and his father is () years old.

Dad is 30 years older than Xiao Xiao. Next year, my father will be three times as old as Xiao Qiang, and Xiao Qiang will be () years old this year.

6. The father is 27 years older than his son. Four years later, my father is four times older than my son, so my son is () years old this year.

Three basic characteristics of the age problem:

1. The age difference between two people is constant.

2. The age of two people increases or decreases at the same time.

3. The multiple changes of two people's ages.