Use a system of linear equations with two variables and two equations to solve.

A. The startup cost for a boutique is $15,000, and each floral arrangement costs $17 for the boutique to make. If each arrangement is then sold for $25, after how many arrangements does the boutique break even?

B. If a scientist mixed 15% saline solution with 48% saline solution to get 20 gallons of 35% saline solution, how many gallons of 15% and 48% solutions were mixed? Round each to the nearest whole gallon.

C. Admission into an amusement park for 4 children and 2 adults is $133.50. For 6 children and 4 adults, the admission is $235.50. Assuming a different price for children and adults, what is the price of the child ticket and the price of the adult ticket?