14. (15 points) Before a football match, a total of 400 tickets of three categories, A, B, and C, were sold. Category A tickets cost 50 yuan each, Category B tickets cost 40 yuan each, and Category C tickets cost 30 yuan each, generating a total revenue of 15500 yuan. The number of Category B and Category C tickets sold is the same. How many tickets of each category were sold?
【Analysis】Let the number of tickets sold by B be $X$, then the number of tickets sold by C is $x$, and the number of tickets sold by A is $(400-2 x)$. According to “unit price $\times$ quantity $=$ total price,” calculate the total price of tickets A, B, and C respectively, and then list the equation based on “the total price of A tickets + the total price of B tickets + the total price of C tickets $=15500$” to solve.

【Solution】Solution: Let the number of tickets sold by B be $X$, then the number of tickets sold by C is $x$, and the number of tickets sold by A is $(400-2 x)$,
$$
\begin{aligned}
50 \times(400-2 x)+40 x+30 x & =15500, \\
20000-100 x+70 x & =15500, \\
20000-30 x & =15500, \\
x & =150 ;
\end{aligned}
$$

Answer: 100 tickets of class A were sold, and 150 tickets each of class B and class C were sold.