Amixture of alcohol and water contains a total of 36 oz of liquid. there are 9 oz of pure alcohol in the mixture. what percent of the mixture is water? what percent is alcohol?

Tom wants to order tickets online so that he and three of his friends can go to a water park the cost of the tickets is 16.00 per person there is also a 2.50 one-time service fee for ordering tickets online write an expression in term of n that represents the cost for n ordering tickets online