11. (6 points) The ratio of male to female students in schools $A$ and $B$ is $8: 7$ and $30: 31$ respectively. After the two schools merge, the ratio of male to female students is 27: 26. What was the ratio of the total number of students in schools $A$ and $B$ before the merger? $\qquad$ .
11. (6 points) The ratio of male to female students in schools $A$ and $B$ is $8: 7$ and $30: 31$, respectively. After the two schools merge, the ratio of male to female students is $27: 26$. Therefore, the ratio of the total number of students in schools $A$ and $B$ before the merger is $\qquad$ 45: 61.

【Solution】Let the number of male and female students in schools $A$ and $B$ be $8a, 7a, 30b, 31b$, respectively. According to the problem:
$$
\begin{aligned}
(8 a+30 b):(7 a+31 b)= & 27: 26, \\
27 \times(7 a+31 b) & =26 \times(8 a+30 b), \\
189 a+837 b & =208 a+780 b, \\
837 b-780 b & =208 a-189 a, \\
57 b & =19 a
\end{aligned}
$$

So, $a=3b$,
Therefore, the ratio of the total number of students in schools $A$ and $B$ before the merger is:
$$
\begin{aligned}
& (8 a+7 a):(30 b+31 b), \\
= & 15 a: 61 b, \\
= & 45 b: 61 b, \\
= & (45 b \div b):(61 b \div b) \\
= & 45: 61 ;
\end{aligned}
$$

Answer: The ratio of the total number of students in schools $A$ and $B$ before the merger is $45: 61$.
Therefore, the answer is: 45: 61.