Question 476000
Let {{{x}}} = gallons of $3.74 gas to be mixed in
In words:
( cost of $3.03 gas ) + ( cost of $3.74 gas ) = ( cost of $3.28 gas )
given:
Cost of $3.03 gas = {{{ 3.03*30 = 90.9 }}}
Cost of $3.74 gas = {{{ 3.74x }}}
Cost of $3.28 gas = {{{ 3.28*(30 + x) }}}
--------------------------------
{{{ 90.9 + 3.74x = 3.28*(30 + x) }}}
{{{ 90.9 + 3.74x = 98.4 + 3.28x }}}
{{{ .46x = 7.5 }}}
{{{ x = 16.304  }}}
The owner must mix in 16.304 gallons of the $3.74 gas
check answer:
{{{ 90.9 + 3.74x = 3.28*(30 + x) }}}
{{{ 90.9 + 3.74*16.304 = 3.28*(30 + 16.304) }}}
{{{ 90.9 + 60.977 = 3.28*46.304 }}}
{{{ 151.877 = 151.877 }}}
OK