# C89/C99, 29 bytes, 2 versions, score = 14.5

<!-- language: lang-c -->

 #include <stdio.h>
 
 int main() {
 int v = 11 //**/ 11
 + 88;
 printf("C%d\n", v);
 return 0;
 }

`//` style comments aren't recognized in C89.

Golfed version:

<!-- language: lang-c -->

 int v(){return 20//**/2
 +79;}