Question 237454
Let {{{a}}} = number of student tickets sold
Let {{{b}}} = number of adult tickets sold
given:
(1) {{{a + b = 450}}}
(2) {{{3a + 5b = 2000}}}
Multiply both sides of (1) by {{{3}}} and
subtract (1) from (2)
(2) {{{3a + 5b = 2000}}}
(1) {{{-3a -3b = 1350}}}
{{{2b = 650}}}
{{{b = 325}}}
and, since
(1) {{{a + b = 450}}}
(1) {{{a + 325 = 450}}}
{{{a = 450 - 325}}}
{{{a = 125}}}
125 student tickets and 325 adult tickets were sold
check:
(2) {{{3a + 5b = 2000}}}
 (2) {{{3*125 + 5*325 = 2000}}}
{{{375 + 1625 = 2000}}}
{{{2000 = 2000}}}
OK