If I had a seat list and price list according to age;

Lets say 18 and over is $30.00 and under 18 is $20.00 that is for a floor
level seat. A balcony seat is $15.00 if you are 18 and over. It is $10.00 if
you are under 18. Then you have a front row seat that is $40.00 dollars if
you are 18 and over and $35.00 if you are under 18.

I have to determine the price according to age and seat selection.

Any help is sure appreciated I am missing some step but can not figure out
where. I hope I have given enough information. If not let me know...THANKS