Question 167337
number of adults call a and number of students call s

a=2s------->eq.1
3a+2s=824-->eq.2
:
substituting a's value from eq 1 into eq 2. we arrive at {{{3(2s)+2s=824}}}
:
{{{8s=824}}} so {{{s=103}}}
:
therefore a=2(103)=206

{{{highlight(adults-tickets=206)}}}
{{{highlight(student-tickets=103)}}}