Question 698531
Let {{{ a }}} = kg of cashew nuts needed
given:
{{{ ( 66a + 85*10 ) / ( a + 10 ) = 71 }}}
This is simply
[ (cost/kg)x(kg) + (cost/kg)x(kg) ] / ( kg + kg ) = cost/kg
{{{ 66a + 850 = 71*( a + 10 ) }}}
{{{ 66a + 850 = 71a + 710 }}}
{{{ 5a = 140 }}}
{{{ a = 28 }}}
28 kg of cashew nuts are needed
check answer:
{{{ ( 66a + 85*10 ) / ( a + 10 ) = 71 }}}
{{{ ( 66*28 + 85*10 ) / ( 28 + 10 ) = 71 }}}
{{{ ( 1848 + 850 ) / 38 = 71 }}}
{{{ 2698 / 38 = 71 }}}
{{{ 2698 = 38*71 }}}
{{{ 2698 = 2698 }}}
OK