Question 122035
Let {{{s}}} = number of students who bought tickets
Let {{{n}}} = number of non-students who bought tickets
{{{2s + 3n = 1912}}}
{{{n + s = 812}}}
{{{n = 812 - s}}}
substitute {{{n}}} in terms of {{{s}}} into first equation
{{{2s + 3(812 - s) = 1912}}}
{{{2s + 2436 - 3s = 1912}}}
{{{s = 2436 - 1912}}}
{{{s = 524}}} answer
check
{{{n = 812 - s}}}
{{{n = 288}}}
{{{2s + 3n = 1912}}}
{{{2*524 + 3*288 = 1912}}}
{{{1048 + 864 = 1912}}}
{{{1912 = 1912}}}
OK