Let A = number of adult tickets, and S = number of student tickets
Then A + S = 300 tickets
the price of an adult ticket is $15, the price of a student ticket is $11, and the desired revenue is $3630
Then $15A + $11S = $3630
solving the first equation for A, we get A = 300t - S
substituting that value in to the second equation, we get
$15(300t - S) + $11S = $3630
$4500t - $15S + $11S = $3630
combining terms, we get $4500t -4t S = $3630
which yields -4t S = -$870; dividing both sides by -4, we get
S = 217.5 tickets
then A = 3200t - 217.5 = 82.5 tickets
Proof: (82.5t x $15/t) + (217.5t x $11/t) = $3630
If the desired revenue were $3640, the values would be even numbers at 215 and 85.
Aaron M.
10/27/15