10. (6 points) This year, the sum of Li Lin and his father's ages is 50 years old. In 4 years, his father's age will be 2 years less than 3 times his age. How many years older is Li Lin's father than him?
【Analysis】In 4 years, the sum of Li Lin and his father's ages will be $50+4 \times 2=58$ years. Let Li Lin's age in 4 years be $x$ years, then his father's age will be $3 x-2$ years. We can set up an equation based on their total age of 58 years to solve the problem.

【Solution】Solution: Let Li Lin's age in 4 years be $x$ years, then his father's age will be $3 x-2$ years. According to the problem, we can set up the equation:
$$
\begin{array}{c}
x+3 x-2=50+4 \times 2, \\
4 x=60, \\
x=15, \\
3 \times 15-2=43 \text { (years), } \\
43-15=28 \text { (years), }
\end{array}
$$

Answer: Li Lin's father is 28 years older than him.
Therefore, the answer is: 28.