Answer
$110$ adult tickets sold and
$215$ senior tickets sold.
Work Step by Step
Let $x=$ the number of adult tickets sold and
$y=$ the number of senior tickets sold.
Given: $\left\{\begin{array}{l}
{x+y=325}\\
{9x+7y=2495}\end{array}\right.$
multiply the 1st equation with (-7) and add to the second
$2x=2495-7(325)$
$2x=220$
$x=110$
Back-substitute into $x+y=325$
$110+y=325$
$y=215$
$110$ adult tickets sold and
$215$ senior tickets sold.
