A= B+C
As given, A+B+C = 50000 seats
A+(B+C) = 50000
2A = 50000
A= 25000 seats
Now section A sells seats at $30 each
So, 
Now, B+C = 25000
B = 25000-C
B sells at $24 and C sells at $18
So, 24B+18C = 538800
Now as section A incurs an amount of $750000 from booking, so B and C will incur 1288800-750000 = 538800 where $1288800 is the total booking amount.
24B+18C = 538800


6C = 61200
C = 10200
Now, B = 25000-C
B = 25000 - 10200 = 14800
Hence, section A has 25000 seats
Section B has 14800 seats
Section C has 10200 seats
When you have an equation that has variables and you know the value of those variables, just plug it it. So plugging the vaules we get
Just evaluating we get 4
Answer:
12% = 0.12
Percent means 'per 100'. So, 12% means 12 per 100 or simply 12/100. If you divide 12 by 100, you'll get 0.12