Question 428235
{{{ s }}}= number of students on trip
{{{ a }}} = number of adults on trip
given:
(1) {{{ s + a = 150 }}}
(2) {{{4500a + 2850s = 477000 }}} (in cents)
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Multiply both sides of (1) by {{{2850}}}
and subtract (1) from (2)
(2) {{{4500a + 2850s = 477000 }}}
(1) {{{-2850a - 2850s = -427500 }}}
{{{ 1650a = 49500 }}}
{{{ a = 30 }}}
and, since
(1) {{{ s + a = 150 }}}
(1) {{{ s + 30 = 150 }}}
{{{ s = 120 }}}
There were 30 adults and 120 students
check:
(2) {{{4500a + 2850s = 477000 }}}
(2) {{{4500*30 + 2850*120 = 477000 }}}
{{{ 135000 + 342000 = 477000 }}}
{{{ 477000 = 477000 }}}
OK