Applications of linear equations

Question

Adult tickets to a play cost $2.25 each and student tickets cost $1.75 each. Suppose there are twice as many student tickets sold as adult tickets. If the income from the play was $1,725, how many of each type of ticket were sold?

Answer 1

2.25A + 1.75S = 1725

S=2A

2.25A + 1.75(2A) = 1725

2.25 + 3.50)A = 1725

5.75A = 1725

A = 1725/5.75 = 300 adult tickets

S = 600 student tickets