Question 602868
Let {{{ x }}} = pounds of $40/pound coffee needed
{{{ 40x }}} = cost of $40/pound coffee
{{{ 90*30 = 2700 }}} = cost of $90/pound coffee
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{{{ ( 40x + 2700 ) / ( x + 30 ) = 60 }}}
{{{ 40x + 2700 = 60*( x + 30 ) }}}
{{{ 40x + 2700 = 60x + 1800 }}}
{{{ 20x = 900 }}}
{{{ x = 45 }}}
45 pounds of $40/pound coffee is needed
check:
{{{ ( 40*45 + 2700 ) / ( 45 + 30 ) = 60 }}}
{{{ ( 1800 + 2700 ) / 75 = 60 }}}
{{{ 4500 / 75 = 60 }}}
{{{ 4500 = 4500 }}}
OK