Math word problems

Question

Type in only your numerical answer to the following problem; do not type any words or letters with your answer. Two types of tickets are sold for a concert. Adult tickets cost $12 each, while student tickets each cost $9. A total of 180 tickets are sold, bringing in a total of $1905. How many student tickets were sold?

Answer 1

Let x = number of student tickets sold

Let y =number of adult tickets sold

 

Set up equations

 

 

x + y = 180                      eq1

9x + 12y = 1905                eq2

 

 

Substitute eq1 into eq2

 

9x + 12(180 - x) = 1905

9x + 2160 - 12x = 1905

-3x = -255

   x = 85