Question 615605
Let {{{ a }}} = number of local maps sold
Let {{{ b }}} = number of state maps sold
given:
(1) {{{ a + b = 62 }}}
{{{ 50a + 75b = 3500 }}} ( in cents )
divided both sides by {{{ 25 }}}
(2) {{{ 2a + 3b = 140 }}}
Multiply both sides of (1) and
subtract (1) from (2)
(2) {{{ 2a + 3b = 140 }}}
(1) {{{ -2a - 2b = -124 }}}
{{{ b = 16 }}}
and, since
(1) {{{ a + b = 62 }}}
(1) {{{ a + 16 = 62 }}}
(1) {{{ a = 62 - 16 }}}
(1) {{{ a = 46 }}}
They sold
D. 46 local maps
check:
{{{ 50*46 + 75*16 = 3500 }}} 
{{{ 2300 + 1200 = 3500 }}}
{{{ 3500 = 3500 }}}
OK