In this question, the number of seat of A equal the number total seats on B and C. The equation would be:
A=B=C
Total seat= A+B+C= A+A+A=3A
The total revenue for the stadium is $1,193,400. Then the total number of the seat would be:
revenue= total seats*price per seat
$1,193,400= A * $30 + B*24 + C*18
$1,193,400= A * $30 + A*24 + A*18
$1,193,400= A * $72
A= $1,193,400/ 72
A= 16575
Each section hold 16575 seats